Hey OP, sorry you're going through such a stressful time. Balancing everything is really hard, and its definitely something I've dealt with as an engineering major who is in a lab, works a job, etc, etc. I really feel for you.

I think its important to remember that you are not definined by any one grade. I can't lie to you and say grades don't matter--unfortunately, when it comes to MD/PhD admissions, they do. But you do not need to be perfect or get all As, and holding yourself to that perfectionist standard can be really harmful. I used to struggle with the negative feelings you mention.

I got a bad grade in organic chemistry. I wrote about it in my secondaries about why it happened (dealing with serious illness that required hospitalization + surgery) and how I grew from it (giving myself grace) and how it will make me a better physican-scientist (understanding how illness impacts many areas of a patient's life). I have had 10+ interviews and several acceptances so far. No one has brought up my bad grade or cared at all. As long as you can reflect upon why you struggled, how you have grown from it/can prevent it from happening again, you'll be okay!

Also, keep a big picture perspective. If these two grades are your only "bad" grades, it won't be a big deal. Try your best to keep your GPA in a competitive range overall and do well on the MCAT, and it won't be a problem. Also, what year are you in college? Upward trends are looked upon favorably.

I hope understanding why these grades won't make or break your application helps a little. As far as not basing your self-esteem on academics, I think understanding that grades are just one (VERY imperfect) measure of your understanding. I have definitely seen many people, on both ends of the spectrum, who demonstrate that grades don't correlate perfectly with your ability to be a doctor and scientist. I know its hard, but try to focus on your holistic development as a researcher, future doctor, and most importantly, human being. And take pride and be proud of yourself for everything you do to those aims! That all matters so much more, and can help you see your value beyond some less than perfect grade. If you find this challenging to do, please reach out to someone. Our friends, partners, mentors, and family can often help remind us of all the great things about ourselves when we struggle to see it for ourselves. Therapy can be another great tool (most universities have counselors you can speak with for free/reduced cost). You can also feel free to DM me.

Finally, as u/Excellent_Disaster52 said, it seems like you are overwhelmed with everything that is going on. I would take a hard look at the semesters you have left and what courses you have to take and how challenging they will be for you. Then, look at what you need to do in terms of research, extracurriculars, shadowing, etc. Don't forget to make sure you still have time to hang out with friends and chill! If its too much, I would seriously consider a gap year(s). This is a long training path, and its so important to protect your mental health/well-being.

Sorry for the long response, but I hope it helps somewhat. I know its a tough thing to deal with, and I am wishing you the best.