Bless your heart brother.
So, what I am reading from you is, 'it is right to have these doubts now!'
When did you become so sure that this was right?
Sorry for the many questions. I have an almost similar situation. I have doubts. Sometimes I have so much peace. Other times I am really not sure if it is the best thing.
To be honest, I think we erred in not getting godly premarital counseling. If you are both considering marrying I cannot recommend strongly enough getting good Christian premarital counseling. There are godly organizations out there that offer it.
It is far better to spend money on good premarital counseling than a big fancy wedding. Most people spend a lot of money on getting married and nothing on becoming married.
You both have issues that will interfere with a healthy marriage. (You are both human.) It will be wise to deal with those issues in a guided environment. If you are not committed enough to get premarital counseling, you are not committed enough to be married.
When I received the answer to prayer, "it is better to err on the side of mercy than judgment", I accepted that it was OK to marry if I wanted to. But I still wish we would have sought premarital counseling. For one thing it would have been fun to go through it with the woman I was going to spend the rest of my life with. For another, it would have helped prepare me for a dimension of life I had no experience with. For another, it would have helped both of us understand each other better.
If you don't get good premarital counseling (don't be afraid to do it two or three times) you won't be all you can be for your spouse, nor will she be as prepared as she could be to deal with all your idiosyncrasies nor you hers.
In short I think you should focus more on whether or not this is the right woman for you rather than on what other people think about who you should marry.
If she is not the woman God wants you to marry, then there is no problem. If fasting and prayer and premarital counseling all line up indicating she is the one, then who cares what other people think?