Pre-marriage Communication Problem

I am 24 years old. M engaged with a guy for the last 1 year and we are planning to get married. We are also physically engaged for a while. My parents are not very happy with this relation but they have accepted him for my sake. Now for the last month he has changed completely, it’s not he is calling off the marriage but he is treating me in a strange manner. Whenever I ask anything related to him and his work he gets irritated. Before this he was very loving and caring. My career is not yet settled. I am very upset with this. Shall I go further will this relation or not? I really love him and don’t want to lose him. Please guide.