What to do???

ive been wih my partner for nearly 5 years, we have 3 lovely children 1 from previous relatiosnhip,now ive been one of these people whos parents didnt really give a damn and got shoved from pillow to post most of my childhood,never got shown the real way of parenting.now you can probably imagine with my children ive tried my utter best not to follow in my parents footsteps but unfortunatly made a few mistakes not coping the usual that ost mums go through.my eldest is the one with a different father, i have 2 girls to my partner but since they were born things have gone from bad to worse,i had serious post natal depression which resulted in my partner moving out and taking my daughter with him,he moved back in and left my daughter at his parents, i eventually went to court for residency and won.but hes taken her again,and my partner has now done the same with my youngest and shes 7m old,all becausei asked his parents to have the girls for 2 nights to giveme a break as my partner wasnt lifting a finger.he now wont give my girls back at all and is accusing me of being mentally unfit to look after them because of my upbringing etc.ive been told if i went to court id only get 50/50 but i want my girls back full time im their mum they need me and i need them.my partner thinks we can still have a relationship while all this is going on, hes mentally ripped my head apart and my heart.my eldest misses his sisters.the professionals ive spoke to dont really seem to want to help that much, theyve had words with my partner whos living withhis parents again.but no one has told him to return the girls.what do i do for my girls and for my relationship???