I became asexual from suppressing sexual thoughts

I'm a guy.
When I was 11 I thought of the crazy idea that I could try to control my erections because random erections were a problem for me. Every time I felt my penis becoming erect I tried to squash out any excitement and tried my hardest to suppress and concentrate on shunning thoughts that gave me erections or made me feel horny. One night I saw a woman in a movie dancing in a very sexual way (still 11) and that was probably the peak of me suppressing and convincing myself that I shouldn't get a boner and that it was wrong. Then later that night I couldn't stop thinking of that dancer and I fought with myself for about a whole hour in bed until I thought "Wait this is normal" and I felt a rush of excitement and then nothing. Since then I haven't felt any emotions towards any girls and I haven't felt horny since then at all. I don't get excited and my orgasms are dull. I've been trying so hard to get my sexuality back since then. First I was trying so hard to get rid of it and now I'm trying so hard to get it back. How can I get my true self back? I was born straight. Before that crazy idea I had when I was 11 I liked girls and had no interest in guys. I had one year where I didn't try anything and I was just asexual so that didn't work.

How can I spark my libido? I'm now 18.

Hi, mataepter! You could go to the doctor (maybe your regular doctor), explain what is going on, and ask how you can find out if it might be a physical problem. If it's not that, you could ask them where to find a doc who specializes in this and/or if it might be anxiety or depression.
I think that exercising regularly and a healthy diet might help a bit.

Do you feel attracted to no one and nothing at all?

I have the same problem.

I haven't been horny, except for once in a dream, in over 6 years.

Porn doesn't work, fantasizing doesn't work, sex doesn't work; my last bet is to try and abstain from all things sexual for a year or so to allow my brain to reset. This is just the worst, and there is really no medical literature on it.