"I hate my job" vs "work for myself" is a comparison not many will write about especially those in the second category especially after they transition from the first one.
As you must have figured out by now it is easier said than done, because what in the world are you going to do, unless you have a passion that pays in which case you would have been earning from it anyway.
Your employer looked at what you have done in the past and gave you the job. You may not have been the best but you got the job anyway.
You spoke about Upwork, well hirers on Upwork only pick the best and it does take a lot of time, effort and sleepless nights to be the best online.
On the other hand, you don't have to be the best in your line of work to earn your salary. You get it anyway, if you have clocked in and clocked out at the office.
Here's the best part about a day job, something that no entrepreneurial venture can match except those of Jeff Bezos and his peers who have large profit making companies that they run from home.
You get paid a fixed salary like clockwork on the same day every month year after year, irrespective of how little or how much more you have worked. You might also get a bonus like every other employee notwithstanding whether you have worked for it or not.
Someone who goes to work everyday is counted as a person with a purpose in life. Even if you are earning five figures online, people will look at you with suspicion, as though you're running a drug cartel or a ponzi scheme. Saying "I design websites", "I sell t-shirts online", or "I write books" is not enough for people to believe that you earn a living online, even if you actually do!
Believe me it seems amusing when I say it but after a few years it will drive you up the wall and you will start to lose your self esteem. People will look at you as though you are a good-for-nothing, stay-at-home weirdo. I mean you can't show income proofs and screenshots to everyone who comes to visit you at home, or meets you at a social event, just to show that you have a legit life!
The most polite question would be "how's whatever you're doing online going?" or "how's it going - whatever you do that is?"
What's worse is that most people who work online barely make ends meet, but never admit it.
Most income proofs and earnings screenshots that you get on a google search are fake, designed to drive traffic to blogs or landing pages. "How to fake income proofs in Photoshop" are some of the most watched videos on YouTube. So don't get influenced by what you find online, take it with a pinch of salt, and only believe your own experience if you decide to start something part-time.
I could go on and on, but let me end this post by saying that wherever you are, the other side of the grass always looks greener.
So stick with your day job because it pays the bills and be thankful you have one in these times. I know people who would kill to get a job that pays $2000 per month. You're free to try something new in your spare time, but reaching $2000 per month online or through doing odd jobs is something very few actually achieve.