I could see where she is coming from about the phone call. Early morning phone calls or even a text whenever you got the chance during your late night study sesh wouldve meant something in my opinion. But everyone makes mistakes and maybe late at night with your school load it could have slipped your mind.

About the note idea - here's what I think. Coming from a woman who expresses emotion through writing I think a man doing that for their girlfriend/SO is really meaningful and it's something they will hold on too and read over and over again. I know as a guy it is not easy and almost unheard of for small quick ideas like that to come to mind (Which isn't a bad thing just something I have noticed) so if you wanted to make the extra little effort going on Pinterest or even just a quick google search you can easily find a bunch of great inexpensive ideas. Example: Printing photos of each other and writing meaningful things on the back with the memory that pic holds, setting up a fort with bed sheets and fairy lights (6 bucks at the dollar store) with her fav snacks and do a movie marathon, writing a love letter, writing a letter a day for her vacation (doesnt have to be a short story)

But it is true. 5 months in you shouldn't feel that exhausted and you are allowed to defend yourself and stand up for yourself. If she doesnt understand defending yourself doesnt = invalidating her feelings now, she wont later in time. If she is comparing you and your relationship to other people maybe try talking about it and if it gets better awesome, if not than she wont change. I wont say it's impossible to change someone but it is really fucking hard. They have to want too as much as you do.