Just wish to be a normal couple

Hi, I'm ying from Singapore. I been living in UK past 5 years and recently I moved back to Singapore to take care of my dad. I had a bf in UK, we met each other at work 3 years ago and briefly see each other on a daily basis. He is a quiet gentle man, which is how everyone at work sees him too. People who worked with him for 8 years says "Its strange, I have never seen him having any girlfriend these 8 years." However, last year we got together as a couple and was a shock to everyone around us, which is where the problem lies.. His job requires him to work in a small room on his own without communication with anybody and he lived alone, barely speak to anyone on his daily routine for the past 10 years it creates a kind of anxiety in him and sometimes he hate himself so much he shut himself down. He told me in the beginning of relationship that he can't be like a normal boyfriend who can give me love, care, or say sweet things to me because of this problem. However, I said I understand and it's ok. Sometimes we are so happy together but sometimes when he feel bad about himself, he's a complete different person. 2 months ago I went to visit him, and spent one month with him. It's a wonderful 1 month and he was so happy and we are a happy couple because he is happier now..however a month past and I have to leave, the tears keep falling from his eyes when I was hugging him goodbye and he say he doesn't know what he gonna do when I'm gone by the departure gate... the tears he had and words he said still lingle inside my heart making it a sour feeling every time I recall that moment. However he change back to what he was, we barely talk on skype just online messaging. When he wish to see me on skype (Webcam) he will worried he might upset me as he is angry with himself, and because of that we can't talk for long but every time we make video call on skype, the first expression he had when he sees me, is a big smile and blush. After that his old habit will return and I will always say "Its ok, you did well i will just go" because this is the time he normally will say he can't talk to me anymore. I know about his problems but I can't help him when I'm all the way here in Singapore as I know he is lonely but strongly believe that there's no one in the world who can helped him, because he went lots of therapy, healing and mediation section before he knew me and all failed..I'm not young anymore, I am moving back to UK next year. I love him so much I wish I could help him move out the jail he is trapped in even if he choose someone else instead of me when he's normal it doesn't matter. Sometimes I feel sad, I didn't talk to anyone about this to protect him. I wish to get settled down in a few years time but I doesn't have the confidences he will. Sometimes I have the urge to leave him but I can't bear to as I love him and I don't wish to hurt him. .. I'm a confused bee :( sorry for the long post, wish someone can give me advice.. thanks.

I wouldn't leave him. You will just have to put up with this til next year, then when you guys are together he will be very happy then, you just have to make sure you're never upset because that will bring him down. But it sounds to me it is worth fighting for