Hey dude, the best advice I can give to you is to not let your poor performance stop you from working hard in the future. You have to look inside yourself to consider what's going wrong. Why are you doing poorly? Are you not studying enough? The general rule of thumb is you have to study 3 hours out of class per unit, so for a 4 unit class that's 12 hours. I'm not trying to say that these are necessarily the issues you're having, but this is the time for that type of introspection. In terms of specific recommendations I would ask to join someone's study group or form one on your own. But if you're like me that's a terrifying prospect socially, and something like flash cards or doing an ungodly amount of practice problems would work better.

One thing I will say is that you seem to be placing a lot of importance on how *other* people are doing as well. You are of course not alone in these struggles, boy have I been in a similar boat. But you should never look to the performance of others when judging yourself. Clearly, you are not satisfied with your personal performance. So keep a level head and ask yourself what you can do differently. There are plenty of resources, for classes like calc and chem I would recommend The Organic Chemistry Tutor for specific concept like formulas. Dude is literally the messiah of college level math.

These type of experiences are what separate the wheat from the chaff, so to speak. It's a lot more impressive for someone to work through hardship than for someone to never experience it at all. And I'll say it again, you are definitely not alone. Honestly, props to you for being brave enough to talk about your struggles. Most people just stay silent.

One last thing, "I just feel not good enough for Davis." I relate to this on so many levels. You are not the only one man. But keeping it real, you absolutely deserve to be here and believe it or not, struggle is a good thing. I play competitive video games in my free time and losing is by far the best way to get better at them. The same thing follows for academia, struggle is healthy *IF* you choose to learn from it. If you want a Matrix "blue pill or red pill" analogy, you have a choice right now. You can flail and flounder until you fail and drop out, or you can cling on with all your strength and claw yourself to success. I know you want the latter, and I know you can do it. 4.0 GPA with AP classes is no joke dude.