I'm sorry you're dealing with this. Echoing a bit of what Elio said, maybe consider sharing this with him, whether during a lunch meeting or in an email/text (however you generally communicate), etc., just to see what he says?

" And right now I'm experiencing a particularly tough time in my life and I wish he was still my therapist. Instead, I pretend everything is okay in my life as if I was talking to an acquaintance because I don't know what the boundaries are between us. I don't know what I can discuss with him and what are "therapy things". I miss him as my T."