MM,
Please forgive me if you think I’m out of line with some observations. I don’t usually offer advice on the internet to strangers, but as you can see, many out here share parts of your story.
First, I agree with the others here that it is when God seems far away that our spiritual disciplines come to play. Don’t rely on feelings…they will lie to you. Spend time in prayer, at Mass, in the rosary, or whatever you are able to do. I also find that listening to and singing praise music reminds me of God’s power and love, even when I do not feel it.
Second, and this is where you might think I’m out of line, try to stop thinking about yourself so much. Find some way to serve, and focus on others and on God. He has a way of working in our lives when we’re not looking!
Finally, don’t be in a hurry to get married, and absolutely do not marry this girlfriend if you cannot forgive her for the past. Marriage is hard enough; don’t go into it if you have extra baggage that has not been adequately addressed. I suggest looking at Christian marriage preparation materials even before you are engaged.
And remember, when it is hard for you to pray, others are praying for you.
Peace,
Ellen