Go to school/college, get a career in something you love to do.

figure out the max you can charge that people will continue to pay...if youre not happy, quit that shit

You need to be professional to charge more money.

Repetitive, ordinary tasks are often unpopular. We get bored: they're not inherently stimulating. Furthermore, they give no "ego boost"... it's not like people are going to drive by and honk and wave, yelling "great paint job on that mailbox!", yes? And yet, an awful lot of what needs to be done in life is this kind of work: washing the dishes, sweeping the floors, painting the mailbox. I'm a Zen student... and part of our regular practice is to learn how to do this kind of work in a way that's different than what people usually do. In Zen, one is taught to do each thing whole-heartedly, as if you had never done it before. Pay attention to details, keep your whole mind and heart on the job at hand. Don't go wandering off daydreaming, or get caught up in all the thoughts about how you'd rather be doing something else, or go on and on about how boring it is, and so forth. This is hard to learn, but if you do learn it, it makes a huge difference -- not only in your mailbox job, but in your whole life. Life is always just "this moment", but we rarely notice that. Mostly we're off in the future somewhere, dreaming about how it's all going to work out someday, or back in the past, reminiscing or regretting or wishing we could go back to some time when it was better. But the real power of the mind doesn't become available until one learns to focus on JUST THIS: this moment, this dish in the sink, this mailbox.

Paint houses for $2500 starting.

Try actually putting the mailboxes into the ground or building a brickwork around that mailbox.

Here in the United States you could charge up to $100.00 to paint people mailboxes. But since you don't like doing that then do something you enjoy doing.