Speaking as someone whose drawing is so bad that I'm writing my stories as text... you're a better artist than me.
And looking at your comic, you're pretty damn good. Nothing to be ashamed of there. It's your depression talking, and it's lying to you.
You posted something and get zero interest? That's normal, sadly. It's why a lot of artists are doing commissions for below minimum wage, and why the business of marketing exists (check the rules of any place before you try anything like that, though).
You're trying a new art style and it's not working out? That's also normal. Keep at it until you see what's not working out and fix it, and don't try too hard to be perfect.
The app ate your comic? It sounds like a glitch. Politely ask the admins what might have happened, and read the docs to see if there are rules for being listed.