First, please stop doing your own head in for a minute... BREATHE. It will be alright. You're making the right move by asking for help.
It's very normal to be anxious and scared after coming out of the closet. There are all sorts of social and familial pressures that can make us question our decision. It's OK to question yourself - you're 22, you're still young and figuring yourself out, that's what your 20s are all about! It takes a lot of courage to stand up and admit something that's contradictory to what people expect of you. I came out when I was 23, and I'm proud that you've done it as well - good for you for standing up for yourself!
Sexuality is fluid and doesn't have to be all-defining... I consider labels to be an easy way to help others understand who I am, but I don't consider those labels ALL that I am. It's just a shortcut to understanding so that I and another person can start getting real about who we are a little bit sooner and cut out some of the mindless chatter of small talk. You're a gay man... ok, that means you like men. You're bisexual, ok, that means you like men and women. You're a straight man, ok, that means you like women. I know straight men who will fool around with guys when their GFs are around, but wouldn't consider having sex with a man or look twice at one without their GF present. I know girls who have sex with other girls, but consider themselves straight and are married to men. There are no set rules that say who you are, no matter how much people want you to think there is a single label that defines you. I'm bisexual, came out to friends and family as a lesbian, and am dating a man. Lesbian and straight porn is boring to me, but give me some good gay male porn and I'm happy as a clam! When I fantasize, I fantasize about men AND women. Do you see what I mean? There aren't any rules except for those we LET be imposed upon ourselves.
I'd recommend finding some LGBT support groups in your area and meeting other people who have been through what you're going through. If you're concerned about going to centers and meeting new people, maybe find an LGBT-friendly counselor. Oh wait, you're in the UK? National Health, you'll be on a waiting list for the next 2 years, am I right? Seek out internet forums for LGBT folks and talk, tell your story, listen to theirs, learn from their experiences and see if you learn about yourself from them.
Why don't you let go of some of this pressure you're putting on yourself to fit into a nice neat little box, and instead... have sex with whatever gender you're feeling turned on by. Date whatever gender appeals to you. Have a relationship with whatever gender makes you feel good. What whatever porn turns you on and enjoy it. If you have sex with a man tonight, ok, you had sex with a man. If you meet a woman tomorrow who makes you laugh and you're excited to spend time with, ok, ask her out and now you're dating a woman. You're allowed to be whoever you want to be, but you have to accept and love yourself for who you are at any given moment/