I'm sorry you are going through this. It is painful and it will be a rollercoaster of emotions. I'm still dealing with the loss of a long term T. I wasn't able to talk to my T about ending it because it was due to her terminal illness. You, on the other hand, have 6 to 8 weeks to talk to your T about your emotions with this. Will your T be able to recommend other possible T's for you? It would help if you could start looking for a new T before your current T is gone. I know it helped me to just know that my T had someone in mind for me. It meant she had thought about me and cared what happened to me.
I found out last October that my T was ill. Saw her two more times and that was it. Last time I saw her was Dec. 9th. She's in hospice now. I've been seeing the new T since November. I still cry about old T almost every day, but the pain is slowly subsiding and new T is wonderful and dealing with my pain and easy to talk to. Joining PC and having my eyes opened has been a HUGE help, too!
Nobody's pain from loss is the same, but I would urge you to get with a new T as soon as you can so you can start to deal with all these emotions. You are grieving, and it's totally normal in this situation. You WILL undoubtedly get through this!