Legal advice (domestic violence)

I’m a single mom of a 2 1/2 year old and a one year old, because when I was pregnant with the youngest their father got drunk and started smashing everything in our home with a huge metal weapon and threatened to smash our sons head in and my belly (was pregnant) and all my families heads in too and then off himself, if I left him.. so that I would be alone.. there was more incidents over the years, punching, biting and all kids of hitting.. jealousy rages and points where he would break into my moms home where I would stay while she was at work, don’t bother asking why I stayed so long, it’s all a very long story, and I’m not ready to talk about all of that yet, well the moment he left us in the bathroom in the dark to go grab something in his vehicle in the garage I booked it out of the front door with my son barefoot in the winter, cops and my family were looking for us as well so I ran into them hysterical with my son in my arms I gave him to my sister because their dad came cruising down the road and charges after me and our son but thankfully my stepfather got between us and other ppl did as well.. so he’s been charged with assault on our son, me and my stepfather.. mischief and use of weapon I think.. but after a year it has been diverted into mental health, so next court is in July.. if he had finished I his programs they are dropping everything and I’m scared.. I want to get custody of my babies, so I dont know where to go or who to talk to (I’m in Alberta) is this a good enough case? I’m scared that if I take legal action they will give him 50/50. 😭