If you are having feelings of regrets and guilt, I suggest you discuss this with your gender identity therapist before you go any further in your transition.
You absolutely MUST have this resolved BEFORE you do any surgery. Once you do this surgery, it's nearly impossible/impractical to go back, and if you do go back, then it will never be the same as it was before you did the surgery.
I evaluated and researched those with regrets very in depth before I committed to surgery. One of the big things I saw was the short length of transition for those who regretted their surgeries. Most were under 2.5 years from the start of transition to surgery. They were in a big hurry. IMO based on what I've felt, experienced, seen and undergone emotionally, mentally, psychologically, is that you need lots of time to process the magnititude of what you're doing. The ramifications, the positive and negative consequences. 4 years at least.
For me there's never been any doubts at all, but finances, insurance availability, living situation, college, etc all played in a part in my nearly 5 years of transition (May 14th will be 5 years exactly). I'm thankful for the hiccups, delays, and unexpected things that popped up, because it gave me time to process everything on every level, and to prepare myself mentally, emotionally, psychologically and spiritually for the surgery I'm about to undergo next week. I always looked at the first 31 years of my life and they were complete crap. Angry, worthless, unhappy, miserable, trapped, emotional, confused years...I don't want to go back to that. Not now, not ever. Life has been SO MUCH BETTER since the day I started transition. The difference is night and day.
So take your time, seek out guidance and wisdom from others, sort through your feelings with a professional and let it lead you where it may. Best of luck.