Relationship troubles

The past few months have been great I was really happy and I enjoyed being with my SO, but its now getting to the point where I am really not happy. I suffer from depression and I get like this in relationships but im really not happy on one hand I want to end it but I know that once this phase is over I will want her back I love her to bits but there are things that are just to hard to deal with right now like we had to cancel our plans for Valentines because shes made other plans now (we made ours before) and I am the only one who puts effort into the relationship I dont know what to do tbh and it really sucks