not all woman feel that way. personally size doesnt matter as long as you know how to work it. i dont want o seem rude but im getting the imperssion that your other half like dudes that are fake. alot of woman perfer an average man i mean sex is not painful and they can relax and enjoy one another the natural way. men that have big ones or take med to have one end up paying for it in the long run. they will have problems with erectile disfuction so you dont worry because you are all natural and will stay up.
This has nothing to do with your size and something else is going on in your relationship. Make sure to talk to her in a non-confrontational way. You can say " *girlfriends name*, I really miss being intimate with you and I feel hurt when you push me away. Is there something I am doing wrong or ways I can make it better? I am confused as to what is going on." Then see how it goes. Don't interrupt her and let her talk about how she feels. Communication is very important in any relationship, so learn good communication skills now, which can carry your relationship for years to come.