Wow....I just happened to stumble upon this, im usually on the regular Allnurses side. Um, so my opinion is you need to give her space. She basically told you I want to date you but i dont want to date you. She seemed pretty clear that the time was not now. I guess my personality is somewhat different but how I interpret your post is, it feels kinda feels "clingy". Maybe thats how shes feeling. She went from one relationship, straight to a really intense one, then nursing school. She needs time to decompress, not focus on a relationship and just do what she wants to do. Forcing/begging/pleading will not make it better. It will push her away. Respect her wishes and quit communicating with her. If in a few months you dont hear from her, maybe wait till she is on a school break, send a quick email checking in to see how she is, you can guage from her response then which direction things are headed and how much to push the relationship again. She will have a clearer head and will be able to think more rationally.
Clearly your heartbroken so its hard for you to think of your life with out her right now, but I think you just need to let her be and whatever happens, will if its meant to.
Nursing school can be very intensive and difficult, but it really depends on the individual how they cope, how much effort is put forth ect. When I was in school, (graduated 7 years ago), a did what I had to do to get by. I had time to have fun ect, but the pay off was that my grades were only ok but I was younger and not as focused as I could have been. (that being said, I think im an awesome nurse, I get excelent reveiws ect...nursing school smarts dont always equate to awesome nurses . Your ex...lets call it what it is, clearly wants to focus and do her best. You should encourage it. Unfortunately yes you are hurt, but its not all about you here.
She may just be having a freak out. shes overwhelmed. Maybe talking too much about the future freaked her out a bit. who knows. All im saying is give her time and space. I think when shes able to calm down and when shes ready she will talk to you, its not like she ended it because she thinks your a tool bag. Its just that the time is not good for her right now.
so thats my objective opinion on the matter, hope it helps somewhat. In the meantime, yes your hurt, but focus on yourself, get out there and do stuff, what ever it is you do!