It is not important that emotional needs match up or have different value to each person. What is important is that you and she know what each others needs are and which ones are most important. The idea is to meet each others needs in the way that the other person wants them. Not how you would want them met.
You also said
She said she felt alone...I know for awhile I was feeling like it too, winters are tough cause we go to different schedules...I tried to talk to her about it she just shuts down and doesnt say much.....
This single trait is a strong reason not to marry her or continue the relationship. You will never have good communications if either of you shut down when tough subjects must be addressed. This must be addressed with a good counselor. You cannot trust or really intensly love a woman you cannot talk to when the going gets tough.
Like she said she really doesnt feel like she ever made the desicion that sex was going to happen...and that it was all so fast...she said she wasnt into just more like she didnt say no than really do it....which kinda makes me feel worse and better about it...
I mean if this is something that was gonna destroy a Long term relationship, just seems so worthless....and makes me feel the same...
Ok, the fact that she did not think about what she was doing, and had no boundaries in place to keep her from doing this is VERY VERY bad. She really needs to learn about boundaries and how to protect them. It could be that deep down she doesn't feel that she made a bad decision as no decision in her book is an OK decision. She went the no decision rout which is in fact a decision to cheat.
One can dance around this all you/she wants but the data is celar she chose to have sex with her ex and she did not even think twice about it.
You two need to talk deeply and address what would allow her to make that decision. Again a good counselor is required.
Finally, I would keep that ring in my pocket if I were you. A lot of learning and healing must occur before that makes sense.