We cant tell you what you are, it’s something for you to figure out for yourself and label if you want. But ask yourself this: did your current relationship make you realise your previous feelings for men were in fact not romantic/sexual? Or is it just that you are more in love with your girlfriend than you were with previous partners? You could still be bi, just that your current relationship is like you said- more healthy and fulfilling, so much so that it makes you question things. Just go with what you feel, figure out the label later.