Me and my girlfriend of over one year who visits the same school and classes as me had planned to go to therapy (where only she gets it and I wait outside for around 1 hour). We planned this 2 weeks ago, but now I had to cancel the meeting because school ended about 2.5 hours earlier than it did for her because she has to go to another class, which is unusual because this rarely happens. I said that waiting 3-3,5 hours is too much, and that I'm sorry that I couldn't go with her (this is probably the first or second time I wanted to cancel plans in over a year) and she says now that she won't talk to me anymore, I'm unreliable and I can be single if I keep doing this.

This has been happening alot lately, where she decides what I do and how I do it, and I do it because I love her (and want to do it because I want to as well). this time I wanted to do what I wanted and not what she want and this is what I get. I feel pressured, a little threatened and don't like the way she is handling this. What should I do?