It is really hard to start living a fuller life when you've narrowed down your world so much and I'd suggest baby steps and being realistic about expectations. The more of a life you get the more you will be able to take decisions more confidently so I'd be wary of trying to change everything all at once.
Maybe you could start by finding one thing you can do for you each week and in the early stages this can just be research. Like one week contacting an old friend you haven't seen for a while and arranging to meet, you don't have to go into everything if you don't want, just enjoy their company. The next week maybe spend some time trying to find an activity to attend or book a massage or go for a walk or whatever gives you joy that you have stopped doing. All you are doing initially is things that you enjoy but have forgotten, I'd be wary of going for everything has to change right now because that's just totally overwhelming.
If you are struggling with what to do as an activity then consider an LGBT social/hobby/sports/activity group, the city I live in (Manchester) is amazing for this kind of thing, LGBT choirs, LGBT badminton, Lesbian and Bi walking groups etc etc but I know not everyone is as lucky.
If you are in the Northwest this might be helpful, (there is social group info as well as support/crisis type stuff despite the title!): https://lgbt.foundation/get-support/for-women/useful-links/
Stonewall also has info on this kind of thing nationally, just set the search term to social: http://www.stonewall.org.uk/help-advice/whats-my-area
International women's Day is coming up and there are all sorts of interesting events coming up across the country that might tempt you out, you can search for these here: https://www.internationalwomensday.com/Events
Good luck and be kind to yourself!