I also wonder if you are beginning to attached to T2 and find that to be a more stable connection for you right now. I would also wonder how I could do therapy with someone who is gone so much of the time.
I'm not sure if you should process these feelings with T1 or T2 but I do think you need to have the freedom to talk about this and have it heard so that you can feel validated in feeling as you do. I almost get the feeling that you believe you should just accept T1's coming and going with little impact on the relationship and this is not so. You have feelings about this and they deserve to be heard.
Sorry T's return did not go as well as you would have hoped.
TN