I don't think you need artistic confidence, but rather confidence in general. Judging from your post, you seem to give an aura of disappointment, regret, and worthlessness. This may sound really cheesy, but try to believe in yourself more. Give yourself that motivation that you CAN do it and you WILL do it. Having a mindset that only pushes you further down might as well be dead already. Instill in yourself a brighter mindset and keep at it. Over time, it will be natural and rote.
THEN focus on artistic confidence. Using that confidence you already have, you can get rid of those obstacles that block your way.
"Why ever even draw again?" Well, ask yourself. Why do you draw? Some people draw because it's their job. For some, it's casual. For some, it's fun. I know I draw because I love to draw. I even push myself to draw in styles that I don't particularly enjoy, but it's to gain a better understanding and breadth of knowledge. When I started out, I thought foundation studies and practices suck (Your usual pots, vases, still life, people, etc.). I thought traditional and old style art sucked. But y'know I did it, and I don't regret it. It taught me so much even though I kinda hated it.
And about your family and friends who criticize your artwork (without constructive criticism I assume), it's kind of a two-way street. It's one thing to ignore them. And honestly, that what I think you should do FOR THE TIME BEING. But once you gain your artistic confidence, and they still say the same thing, you should probably do some studies on how to make your artwork better.
Now there's always that "my family don't approve of me making a living doing art" shit. Either try making a compromise or just ignore them (I really wouldn't do the latter if you're not an adult with a bright future ahead of you). For example, in my position, I do want to go into a field of art, visual stuff, etc., but to my parents (more my mom than dad) art is a low-paying job. As a result, I told myself that I could combine the fields of art and technology and go into a field like the gaming industry.
So that's my advice to you. You can either do something about your situation using the advice or leave it be. It's your choice.
Also, some artistic advice if you need it: It's the little things that count.