HELP! Why can't I study?

I am supposed to be studying for my upcoming exam. But for some unknown reason, I can't seem to concentrate no matter what I do. I have been trying to study for hours now. I have this semester's final exam tomorrow and I don't know what to do. I am so frustrated. I have tried putting on background music, I want to play video games but I have to study. I am so tired and I just want to sleep. I have to focus on my exams. I am so stupid and lazy. So many people have their lives together and I still can't. I am worried that I won't get a good mark and my parents will be disappointed. I don't know what to do. I am so agitated and I don't know why. I am so annoyed with myself. I have wasted this entire day playing video games all day. I am so regretful and frustrated with myself. I just want to do well on this exam. But my brain is totally fried. I am worried that I won't get good grades. I am so worried and I don't know what to do. I have tried different ways to study. I am so agitated and I don't know what to do. I smoke weed and I am a 20 year old college student. I don't know if it affects me. I don't know what to do. I have been this way for as long as I can remember. I am so frustrated. I am so stupid. I am just so mad and agitated.<br><br>&#x200B;<br><br>What can I do?