If I were your parents I would be overjoyed that you did so well in the first semester, but that’s my opinion.
Quit being so hard on yourself you’re doing a great job. Listen to your brain and your heart 
you’re doing fine.
Find a volunteer position that has you in a position of helping others.
It may help later with your med school apps.
Don’t share any of your personal grades with anyone, that’s your business not theirs:
“How do you do on that Chem test?”
“I did OK”
“Yes but what did you get?”
“I don’t remember the number . . . .”
if pushed further,
“not important”
If pushed even further. . . “Why is my grade so important to you?”
If the concern were genuine, you wouldn’t be constantly asked what your grade was. This is a power trip on the part of your roommate. She wants to feel a lot more superior to you. Don’t give her that power.
Deal with your sanity first then, if you want, you can cater to others. Cal is tough.
If you made it through the first semester, you can make it through all four years.
You’ll be fine. And as far as relationships go, they will come to you; you’ll see.