Back to solicitor, unsure of what to do

[Wereonourway]

Myself and ex split in August. We have a 2 yr old ds.
Initially contact with ex was 2x overnight each week and informal access in between.
This turned into me just working round him, no flexibility from him, lots of verbal abuse from him so I went to a solicitor to formalise things from my end and to show I was being reasonable and fair and that I wasn't alone iykwim?
Ex never approached a solicitor and basically bullied ne into agreeing to the 2 x overnight plus every Sunday day time. I wanted every other Sunday but backed down to save myself from verbal abuse and grief.
Asked my solicitor to confirm my agreement to this in writing, this was in October.
Since then ex has 'pissed about' many many times. Cancelling Sundays for social gatherings, dropping overnights a few times. He also doesn't bath ds, brush his teeth etc and absolutely fails to have ds ready for me on a morning for me to take him to nursery. ( I take him as I work close to nursery but also because ex is driving an untaxed, uninsured van which was deemed unsafe at mot recently).
I've also found out that ex sometimes stays up til 4/5/6 am on Sunday mornings. I strongly suspect he was drinking on at least 2 of these occasions but cannot prove it( only found out after contact so couldn't prevent it).
As Xmas fell on ex's specified night he held this over me. Lots of nasty texts telling me to enjoy turkey for one, not waking up with ds on Xmas morning etc. stupidly( don't think that even covers it) I asked ex to stay at my home in spare room, It would have broke my heart not to be with ds.
This obviously didn't work, I felt bullied by him, I always do. He intimidates and threatens me and I've been stupid enough not to report it so as not to get more abuse.
Xmas has been the last straw for me, I need to act now and have an appointment with my solicitor next week.
I really do not know what to ask/say. Do I reduce contact? Do I put a time limit on him "stepping up"?
His family have rallied round him saying they will support him, his gran will ensure ds has fresh food and bedding( he had no sheets on his mattress on one occasion, and his sister will ensure he has nappies. They have told him to cut down on his Saturday drinking and have told me they are "looking for a good solicitor" to fight his corner.
I have lots of proof of his bullying and threats and dates/ times of failed contacts/ examples of him not having things in for ds etc.
His family think agreement should continue as it is, a 2nd chance if you like but I just don't know anymore.
In an ideal world ex would grow up, start prioritising and be a good dad to ds.
As much as it hurts to be parted from ds I really wouldn't have a problem if ex was providing for him/ doing things properly
Any suggestions/ kind words or advice greatly appreciated. I've had enough of being bullied but simply want what's best for ds, sorry this has been so long.
Felt I needed to talk it out with non biased folk!