HELP . custody advice ?!

Briana • 7.19.16💙4.17.18💙3.21.21🤰🏼23 Years Old ❤️
Me & the father of my child split up when i was 7 months pregnant im due anyday now and ive just been so stressed because we are dating new people and we both have yet to work past stuff really .. Theres still really tough feelings between eachother. We split up cause i caught him cheating and lying and when i gave him a chance to come back he had fone been through two of his exs and made the excuse that he didnt wanna be with me so bad so i moved on . He hasnt really showed that much intrest untill i have moved on and now he constantly asks about my son and is majorly concerned about this new guy being involved with me like hes allowed to move on but i aint . For the women who has experienced something similar how do you deal with it and how do you do visitations if any at all because one of the reasons i left was because his intrest in incest porno .. Like he was looking up incest and family porno in the search bar and hes been sexually abused so i was kind of concerned on my sons part about letting him visit .. Plus my nephew has made a statement saying he has shook his junk at him through his pants and he is too young to even really make something like that up really .. So im worried hes gonna go to court for joint custody or something and him being weird like that plus he smokes pot and his abusive child molesting dad is about to get out of jail and im afraid of him trying to bring my son around it all plus his mom is a alcoholic and lives in filth i just am so scared for my son . My son is safest with me at all times but i want him to have his dad involved too . HELP ME .