I'm sure he will be back.
Imo I think you might benefit from a parenting book. Maybe super nanny?
Naughty children can bring out the worst in us they really can. I think that once you put some consistent strategies in place to deal with his behaviour then things will start to improve.
Parenting is really hard without the added stress of other things.
You could probably get this book from the library.
It's important to do something because if nothing changes, nothing will change. Your approach towards his behaviour is what needs to change.
I see your feeling down about how you feel about your son at times. Tell yourself this:
'He didn't ask to be born, it was my choice and so I have to do what is right and best for him'
Repeat in times of stress to yourself.
How we parent our children has a massive impact upon their behaviour. I hate the way your DP talks about your son. Between them both is you. Try to explain to your DP that if he was your little boy how would he feel if his father was saying those things about him?
Don't let your boy become the naughty child, blamed for everything, dp taking moods out on him.
Just no. You are better than that and you were given your son back for a reason. You love your son. He's only a temporary fixture too, time flies before you know it he will be grown up and making his own way in the world.
To do that properly though he needs a good, solid, stable upbringing.