I don’t feel I’m good at anything. I have a 9-5 job and I do martial arts but lately I just feel like I’m not good at those or anything for that matter. I see all of these talented people making it and I’m just sitting here thinking that I have to work twice as hard as most people and still not be successful. I’m just not good or special at anything I do. Art, music, video games, sports, comedy, I tried them all and I suck at all of them.

Should I just quit everything and start over or keep going? Keep in mind I hate my job but it pays well.

Well I don't think that quitting everything and starting over is a good idea, but neither is just staying the same if it doesn't make you happy. Honestly I don't think there is a good enough reason to be alive if you are not happy and are not working towards being happy.
You should search around for more things you might enjoy for sure since I don't think it is possible to have tried anything.
Only after you have really scraped the bottom of the barrel, then I would recommend saving up money and moving somewhere else, meet a different set of people at a different environment and see if anything is different. Sometimes our surroundings really put a dumper on us.

I mean I tried art, music, sports, video games, school, etc., and I’m just not good or talented in any of those things. For example, I won a martial arts tournament that took me nearly 6 years to win yet my friend who has trained for barely over a year wins it even easier than I did against better people. And I’m considering quitting martial arts since I’m not as good as I want to be nor do I think I’ll ever be that good.
I gave myself a deadline. If I don’t succeed and achieve my goal by New Year’s 2020, then I’m just going to... well, not live anymore. I can’t take being unhappy. I can’t take seeing people who don’t try nearly as hard as I do yet succeed while I’m not even scraping by.
I’m just a waste of space at this point.

I think you are so great. Maybe you took 6 years but you win, right? Hard-work won't bertay you. It is real! Don't look to other person, just do something what you like. Maybe you think you are bad, but for me it is great. Don't give up! World is not bad as you think... #sorryforbadgrammar

My suggestion: Go to the Naruto wiki and read Rock Lee's article. Then, maybe start trying to be positive. I know that sounds insensitive, but if you start reminding yourself that the glass is also half full...

Well, you do martial arts! So you're obviously in shape, right? And you make good money from your job, so you have more finance to find out what you're good at!

And hey, just because you're bad at some video games doesn't mean you're bad at all of them!

Sports are lame, don't even try. You're better off keeping with martial arts. Who knows, maybe you'll meet some girl or guy, they'll go on a date, you'll walk home, then BAM! Knifepoint mugging! Then, you're a big damn hero and save the day.

Music takes a long time, even rock stars needed to train for decades.

School is overrated, I've never used anything I learned pre-college.

Art is hard, but anyone can be good at it if they keep at it long enough.
Also... this may seem harsh, but dying would be kinda pathetic. If you're not talented at anything, that just means you need to be good at working hard! I'll tell you as someone that is kinda talented at almost everything I do, hard work is my bane. I often get shown up by people who work hard, so it works.

And hey, you aren't a waste of space as long as you contribute to the economy. Even if you're just a tiny gear in a big machine, that big machine would break if gears just started falling out.

Or you know, go be a vigilante. There are always people that need saving.

>>5 it’s not so much a matter of whether I won or not, it’s that it was such a huge accomplishment for me yet when my friend won it in less than 1/5th of the time I put in it felt like what I accomplished was so miniscule that I almost threw the trophy out.
>>6 I like Lee a lot. I’m like him except I have no one to guide me. He had Guy. I have no one that can guide me like he did.
Oh don’t even get me started on girls. They don’t even look at me. And my friend that won? Yeah he has a pretty gf while I’m always third-wheeling. I’m supposed to be part of his wedding as a groomsmen yet I really don’t feel up to it. Fuck, I’m not even buying the suit he wants me to.
I might just tell him to find someone else.
If you watched the latest Attack on Titan episode, Keith was talkin. About people who are and are not special. Look at Grisha. He was loved by everyone and even got the girl Keith loved. What did Keith get? Jack shit. I’m basically Keith. Nothing special. Just another brick in the wall.