How do I stop yoga from improving my mental health?

I have started doing yoga. My aim is to improve flexibility and be calm at my martial arts training ( i had some mental issues and i use to panic and get nervous at the training). Only after like a few day i felt a big difference while training. I was soo calm.
I have always been very shy and self absored always. I know that I have some disorders and mentally I am not okay. But i heard that yoga helps with mental health. As crazy as this sounds I don't want my disorders, quirks etc to go away. I just want to stay the way I am.
I don't want yoga to help me with my disorders. I like the craziness inside me.
help to solve my problem. please guys. I just want to improve my flexibility and be good at training. that all. I don't wanna change anything else about me. I want the disorder, neatness, craziness to stay inside me. How do I do that?
My ques really is how do i let the disorders, neatness, craziness...stay with me while continuing to practice yoga.
Like it's okay thing like my concentration etc improve. But the disorders, how I am now, I dnt wanna change this at all. I actually like this "craziness" inside me. Plus, I don't really want this change, it's not cool. I am so not okay with this.
I just want to improve my flexibility and be okay at training. That's all. Maybe some people are thinking that i just want attention. That's not true, i promise. I hate being the centre of attention.
So anyways, i was thinking like when breathing, I could focus on me being good at training only. Just focus on training and nothing else.
I know to everyone this sounds crazy but I promise not joking. I am serious about this problem.
Cheers,
Princess