I have been with my boyfriend now for over a year and our relationship is great when it comes to me and him... however, I am struggling to cope with the situation around his ex and his son.

they split up over 2 years ago now. My boyfriend has opened up to me about how mentally abusive the relationship was with his ex. And I have seen it first hand on her messages to him. She appears to hate him but seemingly uses their son as a weapon. My boyfriend is an amazing parent and I am sure she is to.. however if he doesn't do what she says or demands (money.. she dictates when he sees his child.. and she is always asking for more and more money.. she even asked him to come and empty the bin at their home and replace the boiler) my partner works full time and so does she, there is no civil court things in place , they just co parent themselves.. but she tends to want things her way or she can have quite a nasty tongue and tell him he's a rubbish dad .. the list goes on. 
my boyfriend and his ex both got a home together and when they split up.. she demanded she got to stay in the home with the child and demanded my boyfriends car.. to which he left it all with her. 
she has now wrote his car off, however, we have not heard what she has done with the car .. my boyfriend doesn't want to ask as he is worried that would cause an argument. And now she wants to move her new partner and his son in to the home that is legally my boyfriends and hers.. but she will not buy my boyfriend out the mortgage. Her partner is going to be renting his property out whilst he lives in my boyfriends home, also my boyfriend is still paying the mortgage to this day and child maintenance on top to and provides for his child when he has him. 
 

his ex refuses to drop off or pick up her child and even expects me to do the driving as she says "she doesn't pay for petrol to drive that far" baring in mind the journey is 30 minutes but she blames my boyfriend for moving 30 minutes away! And even guilts my boyfriend in to saying he doesn't spend enough time with his son, my boyfriend moved to where he works and still sees his son. my boyfriend rings his son every night that he doesn't see him, and she either doesn't answer or she answers and holds the phone and allows the child to be rude on the phone, she laughs in the background and the child laughs back with her and the child sometimes plays on his x box and ignores my boyfriend (his dad) even when he's trying to ask his son how was school. 
 

a lot of the time his son is sat in the changing rooms to a gym she takes him to whilst she works out at her partners gym and the child is left sat still in his school uniform playing games on her phone. The child is 8 this year by the way.

the child can be lovley and hasn't yet been rude to me, but a lot of the time is rude and disrespectful towards his dad, and demands from his dad, my boyfriend buys him gifts just to gain some affection from his son, even on Christmas Day bought him a bike and his son was not interested and looked at the other presents and said "I'm sure there is more presents here for me", his son doesn't give me and my boyfriend a second of privacy and is lazy and gives back chat a lot even when being asked to do simple things like getting a shower or tidy his toys away. The child also tells his mum that dad doesn't let him sleep in dads bed anymore, and one night my boyfriend took the bins out and I was still in the home and I checked on the child and he appeared asleep but he told his mum that dad had left him in the house alone which was not true. I have spoken to my boyfriend about this , but I know he guilt parents because of the things his ex says and she has no shame in making horrible comments to my boyfriend infront of his dad. The child back chats a lot and my boyfriend passes it off as "he's just a kid" but the child goes to his room and slams to door and tells me boyfriend to get out of his room when my boyfriend tries to put boundaries in place (my boyfriend doesn't shout as he doesn't need to but tries to be firm) and the child cries or gets an attitude and starts saying to his dad "oh your just a moody dad" 

the child cries when he has to eat at the table , as he has been so used to his mum letting him eat on the couch and he leaves food allover the couch and brushes it on the floor and leaves his plate on the couch. 
 

when my boyfriend has tried to tell his son it is bedtime his son argues and says no and argues why are we not going to bed .. to the point my boyfriend allows him to stay up.

we also got a puppy and the child was playing quite rough with the puppy and I asked him not to as we didn't want the puppy to get used to that and it could hurt him, and the child went home and told his mum that his hands where sore and dads puppy had done it, 

there is so much more going on but I just really need advice , my boyfriend and I love each other , but things are really hard for me to cope with the ex and the sons behaviour, sometimes my partner gets defensive over his son if I have made a comment about his sons behaviour and sometimes my partner cries and says he is aware of it and my partner hasn't put consistent boundaries in place as he feels guilt for lost time after the break up...

any advice.. there is lots more and I am writing this as I am really worried this is breaking down my relationship and I do care for my boyfriend and his son a lot , but I don't know how to help get things back on track and get rid of this toxic energy his ex still has