I actually have felt like you describe, I spent most of my life not really feeling like I could really connect with hardly anyone; both for a romantic relationship or even just real friends. So many people when I was young wanted to party so much and so often when I was hanging out with people I felt like I was just pretending to like things or people, and have fun. I really didn't know how other people did it, as it all seemed so false and was such a struggle and I enjoyed time by myself, or with my family or chatting with people online, so much more.
Overtime, I found friends who were more like myself and when I spent time with them, I found I was really having fun and I did start to care about them. I've had lots of good times since that time, met and kept good friends, had a couple of romantic relationships and even when a couple of life changing things caused me to lose relationships and friends, I've rebuilt new connections with people, new friends and a new romantic relationship. If I had to do it all again, I would have spent less time trying to fit in with the main stream, and would have pursued my own path and interests instead, finding people interested in the same things as I and with values and lifestyles more similar to mine.
You are going to need some time to just recover as well as find yourself, allow yourself the time but also be open to experiences. Mostly pursue the hobbies, interests and things you enjoy and find friends who have similar interests and values as you do. You will likely find that you can relate better to them and that real connections will develop; you won't feel like you are being phoney. You may also find that you have a special person that could turn into a romantic relationship.
Infatuation feels really good and it's hard to avoid that when you met someone you share a certain chemistry with. However, just being infatuated doesn't really indicate the relationship has any long term potential; instead it just indicates you feel passion and that is activated by hormones. This is something that everyone goes through, at least when they are young, and it's fine, however as you learn more about yourself and what you like and as you get to know other people, including a romantic partner, you are likely to move from strong feelings of infatuation and into more deep feelings of love, deep connection on many levels and long term companionship.
A lot of what everyone goes through is sort of a rite of passage; it's not all pleasant and it involves some heart break, loneliness, mistakes, and other unpleasant things but it's all part of getting to know yourself, becoming a mature adult, getting to know other people and making connections and relationships with them. So it's good that you want to pursue some of this and all I can suggest is to take your time, understand that it is a process and most of all, if you don't feel comfortable with the people you are hanging out with - try meeting other people. Try meeting people into the same things you are into, who have similar lifestyles and values as you do. Although diversity in people is great, when it comes down to feeling comfortable with people and not feeling like a phoney, a lot has to due with people similar to us.