You're not wasting your time. I was diagnosed with MDD (major depressive disorder) when I was a teen, and I have been in a few relationships. I am in one now.

Depression is, in it's self, this black hole. You want to communicate with those you love, yet you feel unable or unworthy. You want to be affectionate, yet there feels like there is a wall blocking you and you do not have the strength to move it. It is fantastic that she is seeing a therapist, so she knows she can get the help she needs and begin feeling better. That is a good sign.

You said she had a hysterectomy. We live in a society that teaches girls that they are feminine if they have certain parts, can produce children, etc. She is also going through massive hormone changes which is expected after such a surgery, which can be contributing to her mood. All of these things can pile up on each other and cause insane amounts of stress. But what is great is that she has reached out for help. That takes a lot of guts.

Take care of yourself as well, but realize what she has gone through isn't minor.