I am now experiencing being given less work from this man and having comments picked at about the need for me to talk to my child’s father about helping out more domestically. I have no idea where this comment came from and I asked directly about this and he backtracked and said he was just trying to support me.
let's be clear, this manager is utterly incompetent and living in the 1950s. He is in breach of the Equality Act, and his discriminatory mask has well and truly slipped. He has no right to quiz you about childcare arrangements and should focus on supporting you in your role, ensuring you have what you need to deliver to your objectives.
I feel he is building up a case to say I am not focused on my work and that now I am remote working he can’t give me work (which absolutely isn’t the case) like he could if I was in the office.
Keep focusing on the reality of his action, otherwise your MH could deteriorate- said from experience, but do trust your instincts as they are never far wrong in circumstances like this. Keep a (current and retrospective) note of everything he does include interactions with you, dates and context.
The entire team works from home four days a week so this isn’t true at all.. If he only treats you like this, not giving you sufficient meaningful work to do and you've noticed this happening over time, then you need to have a meeting with him to discuss your current workload, what you used to do compared with what you do now and ask him to comment - the outcome you're looking for is a new supply of meaningful work and being treated the same as other colleagues). Give his the bare facts, and then say "over to you" (figuratively speaking) to find out his side.
I'd ask him directly. Are you trying to push me out, mate? As you ought to know that I like this job, or I used to at any rate, and I'm not going.
I don't agree with @jellyfishperiwinkle (sorry), that's jumping to a foregone conclusion and will make you vulnerable to being shot down in flames, just state the facts re your diminishing workload and get him to state what's happening. If he questions your competence to do the job, then this will lead to him having to tell you what you're actually doing wrong (from his perspective) which is something you can then decide, is either true and correct (how can he help you get back on track) or a misplaced judgement that you need to reassure him isn't the case.
Definitely don't call him 'mate' or any other such over-familiar term, that puts you firmly in the wrong!
Conciliatory is always better than confrontation if you care about your job.