Great question.
I understand you have a history of falling in love too easily (because you have been hungrily seeking a replacement for your father). You are worried that your new relationship will fail like all the others, and wonder how you can protect yourselves from being hurt.
When you speak of being afraid to be hurt again, I think you mean that you are scared that you might have chosen another lover who is like your father, and that he will let you down the way your dad did. (see repetition compulsion and unfinished business in the Advice Archives).
Being conscious of the danger is the first point in your favor. You now sound more aware of what wound you have been attempting to heal by choosing men like your dad. That awareness permits you to see your new boyfriend for who he is, not for who you want him to be. Awareness is the first step.
Until and unless you are aware of what old wound you are trying to heal, you will always be in danger of choosing lovers who are exactly like your father. And, until recently, you were unaware that you were choosing carbon copies of dad. Lack of awareness got you into big trouble.
Point being, you are now aware of the tendency to choose men like dad.
With awareness under you psychological belt, you can now study your boyfriend with a 'cold' eye and see whether he is the kind of person who can meet your needs, as opposed to the kind of person who will frustrate you.
So, consider the wound that you want to heal, then, study your friend. Does he seem to be the type of person who is capable of giving what you need? What do you know about his past relationships? Why did they end? Find out all you can about him. And, make sure that you see him for what he is, not what you wish he would be. Bottom line, when we choose lovers who are like the parents that let us down, they will never give us the healing that we need. They are incapable of giving more than we received the first time around. (Clue: if your lover is frustrating you like a parent did, your mind is setting you up for a repetition).
So, first be aware, second study.
And, finally, hold the reins of your heart. Do not pour yourself into this man and this relationship until you have put some time into the relationship. Watch how he behaves and treats you after the honeymoon phase. Watch how he handles you when you are angry with him. In other words, don't pour yourself into him and the relationship until you have more time and information under your belt.
If this man continues to be responsive to you, after the 6 months grace period, things are looking good.
Also, when it is up and running, take my Compatibility Test which will give you a very clear picture on whether or not this man is right for you, or just another 'dad' who will break your heart.
Let me know how you make out.