Coming on here and sharing how you feel is a really good start to finding ways to feel better. Have you contacted the support people at uni? The uni itself will have support in place, and there is probably something run by the student union as well - have a look around on the uni and student union websites. Lots of unis also have a Nightline which you can phone and talk to someone during the night. Talking to someone will help you feel a bit better, and they may be able to give you suggestions about things you could join in with. If that feels too difficult, copy the post you have posted here and send it to the support people at uni, so they can help you.
Moving to uni is huge and lots of people do find it difficult and overwhelming. It is more difficult at the moment because of Covid - as you say it is more difficuly to meet people who are more like you - and there will be plenty of them out there.
Are there any societies you can join who maybe are doing something in person or even on-line - something you can join in with which you enjoy? Is there any sport going on which you could join in with, even if you are not that sporty. Has your course actually started yet? You might feel better once you actually have something to do. Have you found any whatsapp or Facebook groups for others doing your course? You might be able to meet up with one or two people on those, even if it's just outside to go for a walk and talk about your subject.
I think you need to go out for a walk each day too - even if it's just to a shop to buy yourself a sandwich or something else you enjoy to eat - you will start to feel worse if you don't eat, and you will feel worse if you just stay indoors. It can be difficult to motivate yourself to do this but it will make a difference.
Try and cope with one day at a time - find one thing to do each day which takes you out of your flat. Tell yourself that you can cope until the end of today/this week/this month/ this year. Remind yourself of why you want to study your subject, what excites you about it, why you decided to go to uni.
But at the end of the day, if you have tried all these, and really reached out and spoken to people about how you feel, but still feel the same way,
it might be better to go home. But not yet, not until you have given yourself a really good try at making in work.
I hope you find some people - even just one person- to connect with, and things start to feel better soon