How do I stop sabotaging myself?

I'm probably the last person who could help you with that because I think I have the same problem... but I can tell you you're not the only one. It's been that way for me for at least 6 years... which is how long it took me to finish college, studying all night then missing the test, working hard on assignments and never handing them in, posting a resume and not following up when people email me with job offers...

If any of that sounds familiar, it's not laziness or self-hate. Laziness implies that you don't care, and that's the perception people have of "underachievers", but obviously you do care or you wouldn't be here asking the question. You also wouldn't have been getting an A in the class to begin with. Hating yourself isn't it either, or you wouldn't be trying to better yourself. Asking for help I think qualifies as such.

Procrastination, perfectionism, anxiety and impulsiveness are probably closer to the truth. You may want to try speaking with a psychologist about it... it hasn't been much help for me to be honest, but perhaps you'll have better luck. If any of this is helpful, feel free to email me if you have any questions. Most importantly don't beat yourself up over it and don't be shy to ask anyone for help. Best of luck to you.

You see a problem so you're well on your way to fixing it. Really all you need to do is want it bad enough. Try writing down your responsibilities on a calendar. At the end of every day put a check next to everything you accomplished that you set out to do. This way as you look back you can see how much you've done and tell yourself "I made it this far, why should I stop now?" When things start overwhelming you don't just say "I'm better then this." Instead BE better. So you failed at something. So what? One failure doesn't lead to another unless you let it. You have complete control over your life.

maybe everything is being handed to you and what you need is a challenge. try taking harder classes