What to do with this insecurities

I usually don’t post anything but maybe you guys can help me!! I got separated for my husband for a year now

We were in a very toxic relationship and I couldn’t deal with that anymore.. we were together for 11 years

a month after getting separated from my husband a guy from work ask me out.. at the beginning I thought I shouldn’t because I was so hurt my husband used to cheat on me so many times anyways after thinking about it I go head and start talking to him about a month after we started dating.. he’s an amazing guy I love been around him and he makes me happy but at the same time I become really jealous and insecure every time he talks to other woman at work and he’s very friendly and now I feel I may destroy this relationship do to what I went through with my ex... any good suggestions?? Please help I don’t want to loose this good man but I can’t help feeling so jealous..