Does this make me a bad mother?

Me and my ex husband have separated since October. He sees her 3/4 times a week, including 1/2 overnight stays. I feel so lonely when my daughter is staying with her dad, i just feel empty and lost. Last week I had just booked a last minute trip to Istanbul for the following day. I had met a guy out there and we just hit it off straight away, we had an instant connection, really got on. We have been speaking and desperately want to meet each other again. I am thinking of going to Istanbul for 2/3 nights to go and see him. Is this selfish of me? My mum is very old-school and says I should spend all my time with my daughter (who’s 2), and focus on building other relationships later on when she’s a bit older. I cant help but feel so drawn to this guy ive met, and my daughter would just spend maybe 1/2 nights extra with her dad :(