What to do about this girl?

So I got this girl problem. This may be a bit long but maybe some of you can help me. So there is this girl that I met online about a 1.5 years ago we are long distance but we have gotten very very close and became best friends. The thing is I have very strong feelings for her. Now we have dated about 4 different times, but each time we date, we date for about 2 weeks and than she tells me she is losing her feelings for me and we break up( I thinking that this might also be because of the distance but I dunno)and I am willing always travel there or to move there) but this last time we dated for 2 months and it seemed we were getting really serious. She had told me her feelings were strong, that I was perfect and that she loved me, and I felt exactly the same about her. So I decided to make a trip to go meet up and visit with her. Now when I see someone new for the first time I get kinda very shy, quiet and nervous and dont really act myself, it takes me a while to find like my comfort zone. So when I went there thats what happend , I was very quiet and nervous and didnt act myself. But while I was there it didnt seem to go all that bad, we got along, we cuddled, kissed, and even had sex a couple of times. Now when I left and got home she was still telling me she loved me and that her feelings got so much stronger. Untill a couple days later where she told me she was loosing her feelings again and that being with me, since I was quiet and stuff she realized I wasnt her type so she broke up with me. Now I tried explaining to her that I was being queit and not acting myself because I was nervous, and I asked her if we will ever get back together and she said maybe but she cant predict the future. Now I do keep hoping she does come back because after all she has came back to me a couple times before. She loves me for who I am over the phone and I wanna show her thats who I really am in real person, the unnervous and real me and not the one she saw when I was there and nervous.now there is a bit of an age difference im 22 she is 16 and I personnaly dont see a problem with that, but sometimes I wonder if its just her age that she doesnt know exactly what she wants at the moment? Because deep down I believe she is the most perfect girl ever for me, everything I could possibly ask for in a girl she has, I would do anything and everything for her and my feelings are very strong and I love her to death. But am I just wasting my time? Should I try and wait for her or should I try to move on?