Confused on career change and an Ex back in my life?

My question involves my confusion on if I should swap careers, mixed with an ex back in my life that likely shouldn’t be but can’t let go.

I worked on an ambulance for years, it was fun but not my degree, I met an ER nurse who flies with helicopters/planes for some emergency calls, our chemistry was explosive and got serious fast. I got a new job in my degree, moved away and we stayed in touch, talking/seeing each other.

My job is decent, but it’s kind of boring. I miss the ambulance/emergencies even though I thought I was burning out. The major problem comes in that my ex would ALWAYS talk about huge rescues she was on (her job) and it was make me really, really question my job and wish in a way I was back in it.

My rationalization was like this ‘On ambulance we dealt with 5% cool calls, most were really stupid/useless, her in flights is ONLY the good ones’ thus I began this insane envy of her job, which she happily played up. (I think she was narcissistic honestly).

Further…it came to be revealed that she was apparently married but only together for the kids, I didn’t know until very near when I ended it with her. I was torn apart because on one hand I idolized her so completely yet on other she essentially deceived me. I do believe her but not sure this is something to just be swept over, yet I liked her so much.

I cut her out for months, and started moving on, but still had that desire to get back into rescue and the lure of the air ambulance was/is very strong. I would have to go to school and get my nursing degree (guy with nursing…?)

I saw her at a medical conference I was at to maintain my certs…it was a weird day, I remembered I like medicine and also that I liked her. I resisted her then, but we went back to talking on the phone.

I am really confused about if I should even let her in my life again, I think she does ‘love’ me, but she is legally still married. Beyond that her job is something I literally cannot get past as it was tied so strongly to me on the ambulance and seems SO cool doing air ambulance. There’s some serious inferiority complex going on I totally admit but not sure what to do.

So…essentially I have an ex that’s bad for me but I still love and she is in a job I’ve long wanted to do but not sure I should switch – and its impossible to seperate the job from her and my desires. 
Thanks for any help.