First, may I suggest shopping around for a new therapist? Your therapist’s advice to just “think about all the good things” you’ve got going seems very un-therapeutic to me; he/she sounds like they want you to push down your feelings instead of exploring them…? Which seems odd advice to be dispensed by a therapist. I dunno…
Second, nobody says you have to go through the surgery if you don’t feel ready. You can sit on it, talk it out with a (hopefully, different) therapist or a trusted friend, maybe deal with other life stressors first, etc.
In the meantime, you can also vent it out here if it helps alleviate the alone-ness feeling…you will find many in your same situation, and many others who went through it to the other side.
Hugs & Good luck ❤️