marriage that started out wrong

hello, I need your advice and any help I can get from you..I got married to my bf 9yrs ago because i got pregnant (i was 23 at that time and of legal age)..and he didn't know it wasn't his. a year after we separated when he discovered the truth, he ended our marriage..months after i saw on his social media account that he already has a gf, it broke me so much for i fought for him and even tried to persuade him to come back and let him realize the love we had was so much..after a lot of suffering emotionally i decided to stop going after him and continue living..it's been 9yrs and we both moved on with our lives...he with his live in partner (who is also separated with her husband and with a son), and i with my partner. now, meron na akong 3yr old na anak sa aking live in partner..my first child and my 2nd child is with me..me and my partner wanted to get things right and make things legal so were planning of getting married...my exhusband sent me this form galing sa metropolitan tribunal, asking me to fill it up for our annulment...to be honest im scared of what will happen to me, to my children, and to my partner...for 9yrs i never asked anything from him, and worked hard to support myself and my child..no communication...i admitted to him i got scared at that time of loosing him so i didn't told him...that was 9yrs ago.....

what will happen next?? what will happen to me and my family?
will out marriage be nulled right away considering that we're no longer together for 9yrs and we've moved on???
what about my first child who's carrying his surname?