I need serious input. Idk what to do?

I have a 2 y/o son with a man who is a drug seller/addict. Typically I will have my son from sunday til sunday, and then his dad will have him the same.. A few months ago I went to his house and there was a meth pipe, and he always has weird ppl at his house. Hes had as problem with meth in the past, and hes been acting way crazy... It gets worse every week... I decided that its not safe or healthy for my son to be in that kind of an environment.. So I kept him for two weeks instead of one.. Id rather keep him all the time, and have his dad out of the picture completely.. But idk wth to do.. Hes threatened me, called me names, pretty much does anything he can to make me feel like a pos... When its him, that is the pos.. He wants to turn these problems into a custody battle, which I'm ok with because 1. He hasnt had a job for 8 months, and has a house + utilities that are "magically" getting paid.. The judge will wonder howe he supports himself, let alone a child... 2. He had numerous drug charges and is on probation for a drug related crime. _ I've never been in trouble, I dont do drugs, and ive had a very good job for three years and counting... I seriously just want to call the cops and get his house raided.. When I dropped off my son today him n some girl were down stairs, and I walked in and his other son and some little baby were just left upstairs by themself.... Im not stupid. I know what they were doing... Should I tell him to get his **** together and sober up or he wont be seeing my son anytime soon.. call the cops and leave an anonymous tip that his house is a drug house... What would u do? Im so lost. My son deserves so much better. Ugh.....