Is my fiancé having any other relationship?

My fiancé initially cared for me a lot and use to spend quality time with me by hanging out here and there. But after that there was a financial upset and career demotion in his life and we were unable to go out frequently as before but his extravagant way of lifestyle didnt change. He developed a sort of negligence, arrogance towards me. I thought it as result of his sudden financial problem. But now he is financially secure but his attitude has changed towards me. There’s strange sort of detaching attitude towards me. I realized he is hiding something and after lot many questions he told me that he was out of his job for years and that he has taken money from home and others to meet up expenses. He was telling lies to me that he was working. But he was unable to give the clarification for this neglecting and detaching attitude towards me when now his job is back. He accuses me falsely to be very demanding. Is my fiancé having any other affair and has told this story of unemployment just to divert my mind?