Took me 5 yr (twice a week) to truly open up about my past to my T (who is great for me BTW)... so 4 months sound like nothing. Guess I'm a bit extreme but still.
I would not use the word blame here. I guess you either are a good fit with your T or you aren't- no one's fault. Do you like your TT? Or do you think s.o. else might be a better fit for you? Talking about it with TT sounds like a great idea- better than talking about it with your LCM, I think.
Also, I think your "connection" (I just don't know how to put it better, sorry) with LCM is not stg I would compare your RS with TT with. Even she, your LCM, said she doesn't want to be your T (and do the hard stuff with you). Frankly, I'm not sure what does she want to do with you (she could be still helping you, I'm not saying she can't) but this is NOT how the vast majority of T-RS works/looks. So please, just make sure you're not comparing those two.

I don't think anyone is at fault in your relationship with your trauma T. You've only been with her for 4 months - and how regularly do you see her? Is it weekly? If it's not weekly, then you really, really, haven't spent much time with her yet. Even weekly isn't much.

I'm not sure about you, but I know that if I was going to be seeing a specialist for a certain issue... I'd probably close up even more than normal and be on the defensive. I'm fairly resistant to trusting people... and the thought of having to dive in with more serious issues would throw up roadblocks as it would feel like it was too much too soon. Is it like that for you at all with your trauma T?

I think switching trauma Ts, at least right now, is a horrible idea. You're transitioning back into your normal life and you've already got two big changes on top of that - you've got the loss of roommates, and you've got the addition of the huge attachment to your LCM. I think throwing in more change, especially when there's nothing showing that it's hugely necessary, would be a really poor choice.