If you haven't gotten where you'd like to be in terms of love and relationship, you're just going to have to try a little harder. Life is full of lessons, and so are your love affairs; but you have to not only take it all in, but put it to use. Trust and faith have likely been an issue for you in your past affairs; maybe you got involved with someone who wasn't trustworthy, or maybe you refused to have faith in your sweetie or in the relationship, and ended up damaging what could have been a good long-term thing.
You have a way of going with the flow of life that isn't very productive in terms of personal growth. You stick with what's comfortable, what's known, instead of facing the scary prospect of the unknown future -- even if what's known and comfortable isn't that great. What you need to learn about both love and life is that it's supposed to be about progress. You're supposed to grow, not continue to repeat the same lessons and patterns over and over again. Making mistakes is fine, as long as you don't repeat them more than a few times. You have the strength and intelligence needed to start living and loving more proactively; you just need to put them to use.