I feel this same way a lot. Before I met my T I didn't feel like I "needed" anyone, but now I feel like I need him. It's not ideal since the relationship costs money, and money I won't have for much longer. It's a bit terrifying to think that when we say goodbye it's goodbye forever, just because of the rules. My T has alluded to the fact we could keep in touch, but I know that means something like a letter a year, and probably a letter I send which he replies a couple sentences to, not really the same as actually being in a relationship with someone.
In some ways the transference has gotten easier but in some ways I love him more than ever. I found this the other week
3 Ways to Get Over Someone You Obsess Over - wikiHow. I'm thinking of trying some of these techniques. It seems especially bad for me because I have no "real" family of my own, and I have made him like family in my mind, which he is not. So losing him will be like mourning my real loss over again. All I can say is I wish I knew this going into therapy.