I am so sorry to hear how you have been feeling, I understand you must feel so let down by those around you and alone. But know how brave, strong and inspiring you are for continuing to do everything you do (especially med school!!) despite how you have been struggling.
I think everyone has provided some very useful advice here and I can say from my own past experience last year during a similar time I was struggling through, I found being open to joining new uni clubs, sports, getting a new job or even saying hi to the person you buy coffee regularly from and starting a conversation - as unappealing and scary these small random ideas may be sounding right now, when I made myself reach out in all these different areas of my life, they eventually all helped me so much in their own way and turned my life around! I started to build all these different connections with people I never expected to ever and I'm so happy to say I have made some amazing, lasting, new great friends as a result.
Hope the last few days have been a little better <3 We are always here <3