Sorry this is so long I need help

So I'm going to start off by saying every deserves there own opinion and I won't take any offence to anyone being honest I'm not a sensitive person you won't brake me with a nasty or honest if you want to call it comment... also sorry for my terrible spelling 🙈. So I'm 28 years old I have 4 beautiful baby's and number is on the way I'm also getting married in August ( pregnant bride ) this story is about my eldest child he's 11 and the most amazing little boy in the world really if you all new him you would agree I was just 16 when I fell pregnant with him set on keeping him and trying to be the best mum I could be back fired on me massively family and his dad all turned there backs on me before my son was born I ended up in a grubby little mother and baby hostel young and alone with a baby I had no idea how to look after I'd never even changed a nappy in my life it was hard really hard I struggled but I did infact I bloody smashed it 💪 he turned out pure and utter perfection I burst with pride every single time I look at him... I grew up quickly and my little family got bigger and bigger I'm couldn't possible be happier.... so hears where it gets sad 😒 2 years ago his dad contacted me asking, pleading, begging for a second change to be a dad to him I was worried anxious confused had no idea what to do because so I decide to leave the decision down to my son I asked him if he wanted to meet him and he did so fast forward the first year of there new father and son relationship it was great there bond was great I was happy they was happy everyone was happy... then the worst thing possible my sons dad had been cheating on his lovely wife who my son adored with some absolute scrub of a women I wouldn't even know where to start telling you about this women there's so much to tell but the most important fact are she has 3 kids of her own that's she has had taken away from her due to emotional neglect 1 of which was adopted the other two got placed with there dad she's not aloud to see any of them and then I find out my sons dad also had another child after my son who's was also taken away and put up for adoption from the minute I find out these facts everything goes down hill he starts letting my boy down not picking him up acting strange just being a absolute ars I give him another change and he chucks it in my face and all because I believe his girlfriend found me a massive threat she would never let him pick his son up or come into my house unless she was with him she wouldn't even let him spend time with my son on his own she was even jealous of a 11 year old she is desperate for a child with him and is one of those thats says she's pregnant every month but it always ends in mc.. he brought my son a laptop for his bday which he never received she got it instead and my son didn't even get a phone call on his bday I'm at my wits and end and Iv now stopped them seeing my son This had all completely messed my son up he's not the happy bubbly little boy he once was he's confidence is lost he's now having to have cancelling.. his dad is trying to talk me around to letting him and his Mrs see him again but I just don't know what to do any more my boy is so broken all my hard work has been undone by his own father and his low life girlfriend 😒😩