I know I'm obsessing. I know this isn't healthy but I really wanna talk to him. Can I write him? Is it okay? Or would it be a terrible mistake I'm gonna regret?

[Background:
My T left me 4 months ago after I became suicidal. He said I needed another kind of therapy called DBT which he wasn't trained in. I had been with him for 2.5 years & had/have lots of transference issues. A few weeks ago I finally found a new T. He's okay. And then last week T1 said he'd see me again if I also did the DBT thing. So I saw the DBT therapist and am gonna start group soon. That makes T1 (who I'm in love with), T2 and DBT-T!]

It was heartbreaking to see T1 again this week. I had so much pain and so much emotion pent up. We don't have a next appointment set up so I'm not sure what's gonna happen next but I do know the DBT-T is supposed to talk to him. I really wanna talk to him so much right now. Would it be horrible if I sent him a letter? We don't even know if he's gonna be my T again for sure.