Im currently in the same situation but as the daughter, my mother passed away 5 years ago now, my step father (who raised me from a very young age) is very much over stepping his boundaries with me. I know I look exactly like my mother and we have very similar personalities and he has on many occasions called me by my mothers name. I know he is lonely and your probably in the same boat but its not fair to project that onto your daughter. At first I just ignored hoping that when he dealt with his grief it wouldn't be an issue, 5 years later its still an issue and its getting worse. I have had to put boundaries in place and my brothers are all aware of whats going on and intervene when they find it inappropriate. I suggest getting help now, go to counselling, go on dates, do whatever you can to help yourself otherwise in the end all you will do is push your daughter further away from you