This has been on for 3years

How do I gather evidence of abuse asides physical abuse . P.S: I am resident in the Uk. Please what laws apply.

Hi so sorry to hear you're through this it's horrible when your partner is abusive your family supposed to understand abuse is abuse you can record him/keep text messages you can screenshot all messages and send them to your email as evidence

I agree ^ voice or video record him and screenshot messages. Sorry, I am not sure of UK laws, but here that would at least help you get a temporary order of protection. Back up everything to like Google drive, so it's not just on your phone (in case he goes thru your phone or breaks it or anything like that).
I'm not sure that cheating itself is abuse, but it sounds like there's more going on. I'm sorry your family doesn't believe you 💕

Try to find professional help for abuse victims and share what you’ve experienced. Once you have an expert in abuse validating you - you will feel better and your family will be more open to it. It’s too rough on you to deal with an abusive spouse and be invalidated by your family.

https://www.victimsupport.org.uk/crime-info/types-crime/domestic-abuse/

I’m sorry you’re going through that. Not sure about UK laws, but like others have said take screenshots of texts, record conversations etc. I know when my sister was going through something similar she would keep a journal and write down when incidents would happen, give as much detail as possible. I’m not a lawyer or psychologist, but if he is cheating to maliciously hurt you then possibly. Does he say things about it when he cheats to hurt you? Can you record it or take screenshots? Maybe write down how those conversations went. If a lot of this is verbal conversation and you can’t record him, try to have the conversations through text so you have proof. And definitely back them up somewhere he can’t access and delete.

im a psychologist, going to a therapist helps, they can do assessments for court, save everything text messages and record conversations, gather as much evidence as you can keep a diary log of events, cheating cannot be used in a child arrangement court but for domestic violence court if hes doing things to know youre gonna hurt, you can also go down the route of him having unprotected sex as a way of medically hurting you.

Thank you so much mamas. I have taken your advice and putting to work your suggestions. I am also looking forward to therapy x