Daughters father not been in touch for 7 months what to do ?

So my beautiful girl age 10 is feeling abandoned by her so called father, we split 8 years ago and he has always been in her life on a regular basis, now for no reason known to me he has decided to forget he has a first born, he has another child to another women who he isn’t with and he still sees her, I’m getting married and we have a very happy settled life at home, I feel he is jealous of the life I have given to her when he is incapable of providing such stability but I just don’t know what to do, I’m so angry and sad that anybody can hurt my little girl, has anybody ever been in this situation before ?