Happiness and pain

Hi, friends…
This letter is written by a boy who doesn’t know what to do because he is afraid of losing the person he loves.
I’m only 19 but I’ve been confronted with many things in life. Last year my life was a complete mess. I lived day by day. Everything was dull; I had nobody beside me until I met her…
It was as if a phoenix was born inside of me. In the beginning I was acting indifferently but one evening I admitted my feelings to her. I expected her to laugh or to tell me that she likes me but I never thought that there could be anything more between us.
However, it happened…
We have already been together for 7 months and our relationship is going deeper.
Unfortunately there is a problem. She is married and has a child. This is not such a big obstacle. But I don’t want to become what separated my parents. I can’t make my heart stop loving her because she is my heart.
Every night I fall asleep with the thought of her, and I wake up with the same thought in the morning. I’m obsessed by her. I want her next to me at night but this is impossible.
We have discussed the idea of living together but this cannot happen at least until I serve my time as a soldier.
As to the age difference, I think this is of no importance. If there is something real between us age is not a problem at all.. Please, tell me what to do. Should I stay or should I go?
Thank you in advance.