Well there is a paternity test you can do early on but it's expensive and invasive not sure if that's a possibility for you....
Go see a doctor or a clinic. If you are worried about judgement maybe call the local women's shelter and ask for a referral to a sensitive clinic/doc. Talk about your options and discuss the likelihood the baby isn't whos you think it is. Do discuss the drinking they will have resources.
Seek help for the drinking and don't let an ******* drive you to drink.
My primary partner teases me about maybe the baby isn't his (it certainly is) but it's just teasing and I know it, way different than shaming and driving you to drink.
Just seek help , I'm in the same situation just not the diff baby daddy , I drink too I'm 17 weeks pregnant and I can't stop I regret it the next day but will go and have another one ,I'm stressed out over family problems,I'm scared to ask my doc for help
Please reach out to your doctors about this. These babies need and deserve their mommas to be healthy. There is help out there. Family problems are no reason to drink. The problems wont go away, they will just intensify for you. I know it is scary as i have been there. You are all worth getting your lives in order. Fetal Alcohol Syndrome (FAS) is real and will affect these babies for life if you dont do something about this. Do what is right here and reach out for that help~