I'm dealing with similar questions/issues. I am aiming to get my procedure done this summer. I currently have a job I love and have been successful in, and am fortunate enough to have a healthy romantic life with some great women.
I've resided to accepting that this procedure is life changing and will require a significant sacrifice through all facets of life (career, personal, etc.) All of the great things I have going in my life (career, women I am casually dating) are going to have to get de-prioritized as I get through this CLL journey.
My breakthrough point was accepting that this is something I know deep in my heart that I want to have done. Height dysphoria is a crippling mental issue that I am determined to get behind me. After accepting that, I simply let go of the anxiety as it relates to my career and dating and prioritized CLL.
A couple questions I asked myself.
1) Time? The longer I wait, the deeper the hole gets. I'm a pretty ambitious guy, and the more I progress in my career, the harder it will become to take 6 months off for a procedure like this.
2) Return on investment from both a $ and time perspective. This is a HUGE investment and the payoff is enjoying the new height and life without height dysphoria. I want to maximize that return on investment, get this over with, and move on with my life.
3) Career - I'm going to shoot for a LOA and I will be secretive about the purpose. If you see a future for you in your current role, I would say do everything you can to keep it. Only if you cannot secure a LOA should you quit.
4) Dating. This varies from individual to individual. If you have a strong connection with the girl you are seeing with potential, you should be honest with her and tell her about what you are about to do. This procedure is way too life changing to hide from somebody you are seriously dating. Plus, it's not fair to her to keep it a secret. Imagine how you would feel if someone you were really serious with hid something from you that was life changing and risky?
Plus, if she is supportive, she could be a huge asset to you during the process, I'm sure the emotional support would be valuable. If she is not supportive and leaves you, then you know it wasn't meant to be. You are doing this procedure for yourself, not her, and if she isn't supportive, then you know she wasn't the one, and it's time to move on.
For me, all of the women I'm seeing, although I care for them and respect them, I don't see a future with. So I've resided to no serious dating leading up CLL as I know I will not be in a healthy state of mind to date. Dating takes two people, and I see dating as not only enjoyment and companionship for me, but a duty and responsibility for me to be there for the other person as they have needs too. During the CLL process, I would be in a physical, mental, and emotional state where I could not be there for another person as 100% of my energy will be reserved for caring for myself and getting through this life changing procedure. The women I'm seeing now are primarily casual/sxxual, but I will definitely be sad to no longer see them/speak to them as often with this, but again, I know what I have to do, I know what my priorities are, and I'm putting this CLL procedure as my #1 priority and I have to push through.
tldr; Take time to really think through what your priorities are. Write them down. List them out. Once you've identified them, your purpose will be clear, and it will give you a solid path to guide you through next steps.
Good luck!