Knowing what you do now, after the experience you have, if you you could go back in time to the beginning, would you do it all again? Do you regret it?
There are a LOT of moments and periods of time I regret because of EMS. However, those experiences drove me to where I am today...so no, I would not change a thing as I am quite content in life. The moments I regret are more so the moments I missed for key people in my life during THEIR special events or times of need. I missed a lot of "firsts" with my kids, a lot of their accomplishments, sports, productions, you name it. I missed a lot of things I wanted to do personally as well....and for a few years I kind of stagnated in EMS. By that, I mean I was happy, I was paid well...but I was going nowhere.
Your question while good, is completely subjective to the responder and while giving you insight to possible outcomes for yourself, it truly means nothing as your personality and situation is unique as is everyone.
So again...yes there is much "to change" but if I did, I would not be who I am today. Better to look forward than behind I say, as whats done is done.