Is it normal to feel like a complete failure?

Well i do not know if it is normal but i feel the same way. I am similar to you although i am not fat. Also i run an online business that i started and i live on my own. But other than that i am totally alone, no friends no girlfriend, no social life, no real hobbies, i just sit around and watch youtube, eat, sleep, repeat...

One thing i do know is that not everyone else has it so amazing. If they all had it so great then why do they feel the need to show everyone how great their life is on facebook. The answer is they probably dont have it so great, they probably feel like shit too.

On the bright side my life is not too hectic. I get to sleep in and do pretty much whatever i want. I can afford to buy things for myself and i have the flexibility to move around if i choose to do so.

So yeah, its not perfect but its not as bad as it sometimes feels to us,

Yes, I think that's more common then you think. Any advice I would give you, would be somewhat hypocritical, because don't feel much different then you - Except I'm actually decent looking which arguably makes me more of a failure then you ...
But since I'm not above hypocrisy, I'm still going to give you some advice, as I had some time to think about how I have ended up where I am.
Stop judging yourself by the lifes of others! You feel like shit because you think you should have that "normal life" - But here's the thing: It's not THAT hard to get a boring job to make enough money to move out, find an acceptable woman and marry her. Even if you're not that attractive, by now you probably could have done that, if you really wanted to. But do you really? Is there maybe a conflict between what you think you SHOULD want and what you actually want? I can't tell you what to do, but please take a moment to just be honest to yourself.
Maybe part of you is actually quite content with the simplicity of the single life - Just like Quintarius. Or maybe like me, you kinda like feeling bad for yourself :)
Maybe you wouldn't want all the responsibility and commitment that comes with the life of a stock photo family.

I'm not saying you are what you are and you can't change - fuck that! Accept where you are (you can't go back) and decide what you want!
Do you want a woman? There's literally billions out there. Open an online Dating account or something.
Do you wan't friends? You say you play video games - That's an interest you share with almost everyone my age. There's a place to start.
You want a career? 30 is not to late to start. Go study something or find a shit job with some opportunities.

Oh, and here's a weird pro tip: Try to not masturbate for some time. It helps to not feel like a pig and can give you some extra energy aswell.

I'm going to go with "no", when you're a complete failure, it's more normal to be in denial about the truth. You seem to be pretty much in touch with, and recognize what a worthless existence you lead, so I think that's not normal.

What would be extraordinary is if you actually took some proactive steps to improve your situation instead of wallowing around in self-pity. At the end of the day (and your life, to be blunt), no one is really going to care if you wasted your life being a pathetic lump that couldn't even be bothered to help itself. So, if you're waiting for someone to come along and tell you it's time to fix this mess you call your life, you're going to be waiting a long time, sunshine.

Now, this is where you come back with all the half-ass excuses for why you are the way you are. Go ahead, do it, I'll not only shoot them down, I blow them to pieces. There is NO EXCUSE for wasting your life, and even less to piss and moan about it while you do.

I am similar to you except that I have an average build and a handful of friends. Sometimes I feel like they are only my friends because then at least they aren't in my position. This feeling probably comes from my insecurities and negative thinking habits. I'll never truly know for sure.
Here's a tip from some friends though. Focus on positives all the time. How to improve yourself, and how to feel happy. There is a fuck ton of stuff you can do to improve your overall well being. You just have to DO IT. These things include: Eating a balanced diet, exercise physically and mentally, clean (everything), get a pet, get religious, etc... Do this stuff and you can say "hey at least I'm trying". The other nice thing is you can suck ass at all these things but it doesn't really matter as long as you're consistent. Just do it. The most important thing to do while doing all this stuff is: NOT BEING AN ASSHOLE TO PEOPLE. You can be frustrated because doing all this stuff is REALLY frustrating at first, but don't lash out on innocent people. Persevere. This will make you stronger.
This is how I gain the strength to climb out my pit of despair. Most days, I think life is too hard. It's mostly because I don't train for it and even if I did I don't know what the payoff will be. Do we get trophy at the end? Who knows. I just don't want to hurt anyone by giving up.

Being like that is more common than you think. I'm often like that too except I'm younger. I do not fit in with my generation. They're all wild, crazy, partying types but I am not a party person and I don't do all those drugs or dress half naked just to fit in. A majority of the time I just keep to myself with people who say they're my friends but really they're just acquaintances.
But it is completely okay! If you don't like something, you have to make an effort to change it. Sitting around complaining won't do anything.
Stay strong! ❤️