Assalamualaikum.

When I was in 7th grade(13 yo) I prayed to allah for my downfall. I was holding a grudge against my mother.I prayed to allah so that he takes away all the opportunities from me. I prayed to allah so that I do not get good scores in 8th grade and 10th grade,fail to get admitted to my favourite college,and fail in 12th grade and I prayed to not get into any good universitity in my country. I also told him to not accept any of my dua pleading him to undo this one. I regret it now.I couldn't do well in 8th grade snd 10th grade, didn't get my favourite college and currently I'm taking my 12th grade test which is obviously not going well.I have to sit for admission tests a few months later and I want go get into a good university. I'm afraid what might happen in near future. What do I do now? How do I ask for Allah's forgiveness?