As gently as I can…unless she is actually unconscious, your wife is making these choices that lead to her cheating on you and leaving your son in your care while she does it. They aren’t just happening to her…she’s making them happen.
You said you cut off her money in attempt to control her drinking. And then you feel responsible for her reaction, which was to then go to bars and hook up with strangers just so she could drink. Basically she’s selling herself for alcohol but you’re blaming yourself? Do you hear how upside down that is?
I would also suggest that you quietly get a consultation with a divorce attorney who can tell you what the process would be in your situation toward getting primary custody. It would be an uphill fight, I’m sure, but knowing what your rights are, especially in light of the immigration issue, may help you feel a little less trapped?
This is a terrible situation and I am so sorry you’re going through it. I am just very glad your child has you to keep him safe. Please keep yourself safe, too…Covid is very much still with us. And that’s not the only ailment she could bring home, you realize…
P.S. Would she agree to be screened for PPD? It’s a pretty small possibility that treating underlying depression would magically solve the alcoholism, especially given everything that’s happened, but if she would consider it?