I just want to get some feelings out and this feels a better place for some reason even though I'm not sure my feelings are actually romantic, more a mix of different types.

I've known for a few weeks that T is getting married this month. I've told her it's a struggle for me and we have discussed it on and off on the lead up to Christmas. Since then, I've not mentioned it as been preoccupied with other stuff. During our most recent session, T forgot to tell me that it's next weekend she's getting married and will be away for a few days. She's been quite unwell and she didn't connect the two things....my session with her being away. She told me in a text later on and apologised profusely for forgetting. When I read the text I felt awful, panicky, frightened. I felt like bursting into tears. The fact she forgot to tell me in person isn't a problem although it would have helped to tell her how I was feeling as she would have been sensitive to this there and then.. We have arranged an earlier session when she isn't away and thankfully it's before the weekend, so I can talk about this before she gets married. But I don't understand why my feelings are so intense. What is wrong with me that is making me feel like this?

I'm not gay, as far as I know. I get attracted to guys.
My female T is getting married to a guy.
The deep seated feeling I'm having is that I'm losing her. T has told me over and over that nothing is going to change, but it FEELS like it's all changing.
I think I'm jealous - really profoundly jealous - of her husband to be, of all the people who will be at her wedding, the fact I'm left out of her life.
I am attracted to her, but it doesn't feel like a sexual thing per se, although physically I do find her attractive.
Maybe I'm in love with her?
Or maybe it's a childlike possessive kind of longing and wanting to push the partner out, like a displaced oedipal complex?

On a more mature, functional level, I'm really happy for her. She's a truly lovely person and no one deserves this more than her. I want her to have a wonderful day. I want her to be happy. I KNOW that it's ridiculous to think anything will change when I see her once a week, time I pay for. I know she will be keen to get back to work after her days off. I know her attention will still be on me in the room, it's not as if it's a whirlwind romance - her guy has been around for a long time, so the marriage won't affect her behaviour towards clients.

But it's killing me inside. It's so upsetting that I'm trying to make some plans for the weekend so I can distract myself and not think about her wedding. Maybe seeing her this week will help me and not make the pain worse. I will have to try and be honest and say I don't know why I feel so badly about this, but my feelings are really intense and I want to understand them.