Hi I'm new here so sorry if this is in the wrong place but desperately need advice
Some background
My son is 17 and I brought him up mostly on my own (His dad was violent and manipulative). Son was always kind and respectful growing up but when he was in year 9 so about 13/14 he started misbehaving and getting in the wrong crowd. He got worse when he turned 15 with drinking etc. Anyway he got with his girlfriend (she's 4 years older, I didn't agree with this obviously but he said I couldn't stop him and I only found out from one of his old friends).
Then about this time last year he told me she was pregnant (he was 16) I was not happy as he also found out in the January but didn't tell me until the June/July and also because of how old she is and also because he was only 16. She gave birth to his son on the 1st of October so he was still 16 (baby was due for the end of October when son would've turned 17 but there wasn't much difference). He used to visit his girlfriend and baby a few times a week but in janaury they got a flat and since then he hasn't texted or called as much and since lockdown he's not called and has only texted a few times. Whenever I call he doesn't answer but he also doesn't Reply to my texts either.
I'm fed up and not sure what to do as we used to be so close
AIBU and can I have some advice please