Really would like advice how to move forward

Are you back in the UK for good, or temporarily?

It sounds like you're already making the positive changes, which is great. Being more healthy and focusing on your studies is really good. It seems like all you're missing is a bit of social interaction.
If you're abroad, do you speak the language? Are there language and/or culture barriers that you feel make socialising harder?

If you can find a way to meet people, even just casually and not necessarily every day, it would probably lift your mood. There are very few people that are happy being completely alone. Are there clubs/societies at your uni you could join? Any interesting places that do things like open mic nights, or something else that means you wouldn't be the centre of attention but you can relax and casually talk to a few people?

Just having some conversations with people and socialising will probably help to lift your mood! Although it can be difficult, especially if you're not naturally an extrovert. There are like minded people around though, you just have to look!

hey thanks so much

i think having more social time would be good... there is a girl who i met through the uni and she wants to do a language exchange meetup so that would be cool..

with certain people i feel really comfortable and enjoy myself

but sometimes i feel so uncomfrable so just avoid things...