totally confused on what to do

:( I am a 38 year old mother of 2 boys . Ages 8 and 12 . We live with there father . I have been with him for 16 years on and off . He suffers from some kind of depression and ansity . has been verbally abusive in the past and now says i wont do it again im sorry . but after the fact that i didnt leave the house sometimes for weeks straight and my self essteam is totally gone . . I reconected with a old high school flame. I am Bipolar and on medication for it since getting on the medication have relized I still love him very much and he feels the same. I don't feel that way for my boys father . I have only stayed since i returned to him in 2006 for the boys not for love . I have been very unhappy for years . now I have tried to tell him i was done with our relationship just 2 days ago and he begs pleads and talks suicidal . so i stayed . again. but I really want out and want to be with the person I love and want to be with . I just want out but dont know how to without a fight to have my boys with me . I have no family to help me or job even the car i drive is in his name i think im trapped totally . the man i have fallen in love with just started working again and has roommates and no car at the moment so he cant help . am i being nutty for wanting to leave someone i dont love anymore for my own happiness ( because high school flame treats me like a queen builds my self esteam up and wants to marry me and has set the date and started planning (if i want to marry him )the boys dad has postponed it at least a dozen times in 15 years ) and not thinking of my boys needing there dad any advice would help im so confused right now .thankyou confused mom of 2