Small claims court help

Bare with me this is a long one 

Split with partner circa 2019 paid for child via an informal agreement every month.

Come to around October 2022 recieve email with a none legally binding document (it was a Google special ) lots of inacrucies and lots of outrageous demands including spousal payments and an increase in CMS payments. Along with this came a simple sentence sign this and if you really want get a solicitor to read it. 

I decided at this point to seek legal advice and inform CMS to move from a informal agreement to a formal agreement. This is were it gets tricky when this email landed it was exactly 7 days to the next informal payment. At this time CMS basically tell me to wait to till the new formal agreement is set up before making a payment and they will give me a payment timetable. So I missed one payment on the informal side but never missed one on the formal side. 

After refusing the payment ex partner took me to small claims court. I sort advice from my solicitor who said fight it small claims court has no jurisdiction over family based arrangements. 

We had to submit evidence etc to decide if it needed to go to a hearing again solicitor assured me it would be dismissed once evidence is read thru. That didn't work and now I have a hearing to attend at end of may.

So fast forward to last few weeks (thank you for bearing with me ) I was told that I had to summit and serve something to the court by the 22nd of April. After repeated phone calls to solicitor I was assured this was all in hand. Now my solicitor has gone incommunicado and refusing to answer phone calls or emails and far as I can tell my solicitor has not submitted these documents.

So looks like I'm going it alone I can no longer afford another solicitor and will be taking the current one to an ombudsmen to recoup money lost.

So can anyone point me in the direction. Of the legal jurisdictions of the small claims court and how family based arrangement s can not be enforced within this court.  

Tia