Please help me

We are not married but have a son almost two. I have two sons aged 12 and 17 from a previous partner. We both purchased a house both putting down deposits of £76k ( me ) and £63 (ex) .
It's held as tenants in common in unequal shares. But on closer inspection of the deed the names are the wrong way round making my deposit the lower amount. The Solicitor who felt with this at the time has admitted that it could be argued that its at fault in court.

I'm currently working self employed 16 hrs a week just braking even after childcare costs and materials ( artist) making around £6 K a year only. He earns £48k per year. I've been paying the mortgage on my own for the past year since he left. He wants to sell now he's finally decided after my tries to put the house on the market before ( mortgage payments are almost £1000 pm)
The equity in the house is around £215k. Me having my share only means I cannot afford to purchase another house, I've tried shared ownership etc but self employed and don't earn enough . I cannot get a mortgage. I'm willing to leave the area me and the children have grown up in to another part of town, properties start are around £145k.

My Solicitor has just informed me that I can get legal aid for a schedule 1 of the children's act. Hopefully we can start negotiating soon, am I being unrealistic to ask for the £145k ? He's been living with parents rent free th past year and is still unwilling to pay me back his half of missed mortgage repayments. I cannot hold onto this house much longer I'm borrowing money from my parents to pay the mortgage each month and worry it may end up reposssed.

Has anyone any experience?

I doubt if you will find anyone on this forum would have experience as to how you deal with a straight bloomer.

If the deed did not accurately represent the intentions of the parties, you may be looking at professional negligence.

You'd need a lawyer who specialises in this field. There aren't too
many because dog doesn't eat dog.

But there are some and they will usually give an informal view of the merits of your case.

LMM