Hotwaterbottle, Please don't panic, just keep calm and see a solicitor.
Hopefully your H isn't as vile as my XH but you got to prepare for the worst.
The allegations XH has thrown at me in court proceedings show that one can get away with pretty much any lies at least in the short run. XH stopped me seeing DS for 3-4 months completely without a few supervised hours a week, and then only agreed by consent to 1 overnight a week, unsupervised, presumably because he wanted to appear more reasonable to the judge.
Our court proceedings have lasted for 10 months and so far the court has not made any decisions because XH's allegations have been so serious that they have had to get the bureaucracy mill involved with social workers, legal guardian etc. All the contact I currently have with DS is because XH agreed to it in court. The law has been powerless so far with regards to this. And the longer it continues the better for XH as he can use the status quo principle in his favour.
I have not ever posed a risk to Ds's wellbeing in any way but XH did make those allegations, and they need to be investigated, and it takes time, - a long time. With no guarantee of outcome.
I sincerely hope your H won't turn as vile as mine, but you need to prepare for the worst. My great mistake was trusting XH, thinking his good nature would never allow him to act like this. But I was 100% wrong on that.
Oh, my XH has also accused me of domestic abuse of all sorts, but those allegations pale in comparison to the allegations he has made regarding DS. So yes, I would urge you to shop around for a lawyer- go and see several, it is money WELL spent at this point, because your H may well go behind your back and suddenly you find yourself at court at a without notice hearing getting accused of DA and being locked out of your own home...
Just thinking of the worst case scenarios here but I do hope your H will not stoop that low and that you are luckier than me.... Have strength and look after yourself 