I am stuck in a damn loop

I am in class 12th, I have anxiety and have Adhd, which often leads me to feel depressed and like an absolute shit. I am very stressed, my exams are in just a few months, I have not studied anything, I try studying, but I feel very unmotivated, depressed and stuck. My 10th-grade board exam results still haunt me. Sometimes, I don't feel like living and continuing. I have dealt with su*cidal thoughts in the past and am still dealing with them. I don't feel like I have any future. I feel very suffocated and stuck. I am tired of pretending that everything is alright, I feel like I am drowning in my own thoughts. I am unable to focus on anything, and I have no motivation to do anything. Whenever I look at my siblings and cousins, I feel very insecure and worthless compared to them. I am very ashamed of myself and very sorry to my parents for disappointing them, even though I know they have high expectations of me, and I am very scared of disappointing them again, like I did before.