If someone has attempted suicide twice, is he suffering from bipolar?

Hello,

I am 24 yrs old and my BF is 21. We have known each other for a year and have been in a relationship for less than a year. This was in my last and his first year of college. Our relationship had a lot of problems since the beginning (6 months), constant fights starting from the first week when we got together. Now I have graduated and moved to a different city, we dont fight much anymore. Things are very normal and loving. We constantly talk on the phone.

He says he loves me very much and wants to get married to me. He asked me if I would marry him the second week we got together, to feel that he is secure, I said "I would if things go well". I love him very much too.

We are from different countries and different faiths.

My concern is that, he told me that he has attempted suicide 2 times in the past and asked me not to tell anyone. He says not even his childhood friend knows about this. His intensity of anger is also very high. He is very defensive and revengful in general and panics easily. He is a smoker.

His suicidal attempts have been bothering me a lot lately.

Please help me. I want to know if this can occur again in his life? or was it just some childhood stress? Can this be bipolar? If it is, what can I do for him?

In past, I have had an extremely bad experience in a relationship with someone who suffered bipolar. It was a nightmare of 2 -3years. I do NOT want something similar to happen to me again. I am very scared to go on in this relationship.

Please advise me...