Hey, I can't necessarily teach you how to have fun, but I have multiple theories as to why drawing isn't fun for you despite having a passion for it. I'll mix the word fun with enjoyment for simplicitys sake.

Skip to bottom for TLDR

First, let's establish the following:

A) There's Enjoyment

B) There's Goals

A) There's physical pleasure

B) There's mental pleasure

IMPORTANT:

The things that are enjoyable, do not necessarily have to fall in line with our goals.

Likewise, the things we hate doing can fall in line with our goals.

Physical pleasure is explained quickly.

Eating chocolate makes us feel physically good because of its taste, even if it doesn't align with our goal of losing weight.

What about mental pleasure though?

In my experience and observations, the things giving us mental pleasures (fun, joy etc) are formed by our past experiences.

Most importantly, SENSE OF ACHIEVEMENT

Things we succeed in give us pleasure. It can be internal or external achievement and praise.

Example:

Think about video games.

Playing video games is enjoyable for most people. There's generally four types of players imo:

a) Completionist

b) Competetive

c) Explorer

d) Builder

However, these players all share a sense of achievement they get when they

a) add a new piece or complete a collection

b) rise over other players

c) find new stuff

d) See their city (etc) taking shape and growing

Keep in mind games aren't actually easy. Think about how Dark Souls players keep playing despite dying over and over. Or how nerve wrecking a league came can be.

How do these game devs keep us coming back? How do they manage to make a challenging, complicated game fun? There's many examples. Dark Souls, Dwarf Fortress, Csgo, League etc

Games are the evidence that hard challenging things are and can be fun and enjoyable (atleast enough to cover the bad bits)

However, games are ingeniously designed.

I studied the most addictive games ( Wow, League etc) and this is what I found:

They have multiple small, medium and big goals to strive for. Short term, medium term and long term.

A Cs in League gives you a bit gold and XP, which leads you closer to a level. You can also kill others, take objectives, and win a game.

You can gain ranks, levels, mastery level etc

Inspect these games closely, you will see just how many things are built into the game that are meant to make you feel PROGRESS and ACHIEVEMENT.

Completion of one of the small goals, like a Cs, new item, level, finishing a quest is always close.

Theres a constant stream of progress and successes that keep you going and coming back.

However, playing video games doesn't fall in line with our goals, usually.

Its so enjoyable, but we all know that we should spend the time more productively.

OKAY SO

What about drawing?

Not everyone, actually most people, do not pick up drawing for the sake of drawing.

Its a tool we need to master to achieve our goals, whether that's creating manga, characters, worlds, designing creatures or landscapes or drawing a portrait.

We have a passion for our characters etc, but not drawing itself.

As mentioned earlier:

The things we like don't always fall in line with what we want to do.

The things we hate sometimes do fall in line with what we want to do.

This is drawing for a lot of people.

We don't actually like drawing, failure and studying , but it moves us towards our goal.

Why does drawing suck? Can I make it fun?

You CAN turn drawing into something fun.

If drawing sucks, 99,999% of the time it's because you haven't felt any big success and praise from it.

Secret is, it's our own fault.

Why?

Drawing right now is tedious because, unlike those video games you don't have any smaller goals in place and aren't seeing constant progress.

Bonus points if you have high expectations.

High expectations do you no good. They will diminish the successes you achieve, thus depriving you of the emotional high that would make drawing fun for you.

BOTTOMLINE

Something is "fun/enjoyable", if our brain has learned to connect it to positive experience, be it physical or mental.

If something sucks or hurts, our brain will make us steer away from that thing.

Something "sucks/is frustrating/boring" if it makes you feel bad.

If you had people cheering you on, praising your art, you had realistic expectations, and constant success and progress, drawing would eventually become something you like.

If you beat yourself up for your "bad pieces", tell yourself you're not good enough, your art makes you feel like inferior Trash, then that creates frustration and sadness.

Again, your brain is super powerful in making you avoid things that make (or made) you feel bad and frustrated.

This is why drawing sucks for most people, and causes them to doubt themselves and their passion.

They'll think things like :

"If I really like art, why am I not drawing?"

"Maybe I'm just deluding myself into thinking I'm an artist"

Heads up:

The very fact that you are pondering about these things and keep coming back to art shows that you care. Theres no reason to doubt your passion and potential.

TLDR

How to make drawing fun?

Just like video games, you need to ingeniously design your art practice and habits so that it can allow you to feel a constant stream of progress and achievement.

How though?

You need clear goals that you can achieve and strive towards. Longterm short term etc, as many as possible.

DaB allows you to "level up" by completing exercises, eventually moving across lectures, and completion.

You can design a calendar and cross of days on which you practiced. There's apps to track your hours.

These things can help to give you a sense of accomplishment, but arent enough.

Whenever you sit down to practice, you need clear goals of what you want to clear. For example, two DaB exercises.

You can't feel a daily sense of accomplishment if you design vague goals like

"Practice perspective today"

How would you know if you achieved a goal?

It needs to have a clear directive and goal.

Also:

Research has shown that once experts reach a certain expertise, once they realise the practice is working, they derive extreme pleasure from performance and practice feels more neutral than boring.

Of course, it will take a while for it to happen.

However, this only needs to happen ONCE.

Once you see the fruits if your labour, trust me, practice will actually feel like fun. The days of beating yourself to do it will be over.

Also, you need lower expectations (aka realistic ones)

If you have high, unrealistic expectations, your results will never feel meaningful enough to give you that sense of success that your brain needs to make drawing fun.

That's all for now. 1500 words yikes.