I need some advice, all input will be appreciated

So i was in a relationship with a Finnish guy and we had a baby.. towards my delivery i moved in with him but had to move out when our baby was barely 6 months because this guy was becoming abusive more than bearable. Previously he had even assaulted me when i was pregnant because we had an argument, which i forgave him a few weeks later because honestly i was so scared to have a baby on my own and also i didn't want the baby to be without his Dad, and well, the guy had apologized and promised never to do that again.
When baby came, he was at first helpful but soon everything was going down, he started drinking every single free time he got save for maybe one weekend, if i say something he became verbally abusive and at one point physically pulling my hair and threatening to hit me. He was very unhelpful and i had to take care of baby all by myself, i cant even get one hour break, even i had to go shower with baby while he sits and plays on his computer. He is either playing or out drinking, it was like we are not there, and i was getting so tired and stressed.We had an arrangement he takes care of the rent while i paid the other bills and buy food. After birth i had jumped from size 34 to a 38 and soon was summer i couldn't hide behind huge jackets anymore so i needed a few tops to tide me over summer, consequently i spend 130€ on some clothes and shoes. When he learnt this he was really mad, i tried to explain but he wont understand. I was to learn later on he had spent all his cash and we were two months behind rent, so he was really mad i bought clothes and we don't have rent, now how was i to know he had lied that he had paid the rent?
Anywho, he became so arrogant, started to kick me out, saying i should find cash fro rent before he comes home or else he don't want to find us home. Then one evening he became so violent i had to run outside with the baby and called his parents who came to help, i was supposed to go to turvakoti the following day but luckily i got an apartment and moved out within the next two weeks. After this we went to social office and agreed he can come anytime to see our baby but he continued to harass me in my home, he comes drunk and if i ask he breaks my stuff and threaten to embarrass me in front of my neighborhood. Now am very scared baby will pick these bad habits from him, and i have now decided to apply for sole custody but he can see baby somewhere whenever he want as long as i am there and also his parents can see baby whenever they want... basically they all can see the baby but i have to pick him afterwards. I should mention that we never got married, thank God!

Please advice me do i have a chance on this and where can i seek legal advice.
Thanks
