Not saying you should take this exact approach, but this is what helped me with similar and intense feelings:

I took close to one month off from seeing her (it was hell). Every...single...day I wrote her a letter and dated it. Some were short and some were so long. The letters ranged from raging anger, admiration, love, painful realization, agony, longing, or just simple gratitude and an update on current events. With each letter I wrote, I would allow myself to be candid and let any words and any emotions come out...I also wrote them exactly as if I were speaking to her, so it felt completely different than a journal. Many days I told myself I was going to give her these letters but in the end I changed my mind.

I could tell you that now I go for a session every week and never call or text her in between sessions (used to frequently) or even get the urge to. I do still think of her, but she doesn't consume my mind 24/7. I long for her to remain in my life after termination but I am now able to think realistically and will be happy if she stays and my life, and it will be bitter-sweet if it is permanently goodbye. When I think of ending therapy with her, sometimes I cry happy tears of gratitude for all she has done for me and how big of a presence her support had in my life for the past year...and I will ALWAYS remember that about her.

I hope my story gives you hope that this will pass and maybe even trigger an idea on how to lessen the intensity of these feelings.