Annulment or divorce?

I am a 36 year old man who married a man from Bangladesh and I married him in the UK where I live and am a citizen of the UK too. I suffer from diabetes type one and paranoid schizophrenia which was diagnosed in 2010. I feel as if my marriage to this guy has broken down. I only got married at the end of July 2015 and feel as if my marriage to this guy wasn't right for me and that I feel now that I am feeling better mentally that I was unable to make the decision of entering a gay marriage. Now I am still in contact with my husband but I feel I don't know what I should do as I want the marriage annulled on mental health grounds. I've been talking with family and friends and my care co-ordinator in the mental health team and they all say I was unable to be making the decision of marriage and I should get the marriage annulled. I've also had friends tell me that I should leave it a few months and then get a divorce instead but I don't know what to do? Anyone gay or straight with a similar experience then please reply to my question. Many thanks in advance