I HATE that my bf was engaged before?

You're a normal woman. Of course there's jealousy, but you know what, their relationship, however intense the feelings involved, is over. It's your turn to love him now. If he is a bit slow to express deep feelings toward you remember that he's been bitten before. Can you imagine being so committed that you would spend the rest of your life with this person, raise a family, grow old together, and then have that wrecked? Some people would lock their heart away forever. He didn't do that. You are in his life now. He opened his heart again, his wounded heart, to you. Take care of it. Love him like no man has ever been loved before. Don't let his past ruin your love and your life together. He shouldn't have to deal with a jealous girlfriend just because of history. Get over the past. Leave it behind you and make the present so enjoyable and the future so promising that he is actually glad the first relationship went sour, so he could have this joy with you. So go love your man to bits. Best of luck with everything.