Housing options for separated single mother

I'm a 29yo single mother who moved back to my parents' with my child. I am separated from my spouse. When the marriage broke down, we had only just applied for our resale property. That was about 3 years ago. The resale flat will reach MOP only in 2026. He had since done up and paid for the reno by himself (as claimed by him, $80k) and has been staying there + collecting rent (and not giving me any portion of the rent). I never stayed there but have been continuing to pay for my share of the house (bank loan) because when i left the marriage, it was still < 3 years of separation. Now there is reasonable ground for divorce given it is > 3 years. But the house (and child) remains a big issue when it comes to asset allocation when proceeding with divorce. Given that i have sole care and control and custody as stated in our deed of separation, i have the rights to own the house, whereas, my spouse (below 35yo) cannot. He has no intention of giving up the house. He asked for the transfer of ownership from me to be given to his current girlfriend (he said that he will appeal to hdb as they have the intention to get married) - 1) is this possible given that he is still technically married to me?

I am in a dilemma; 2) should i fight for the house and buy over his share? I was told my OA has enough to buy over his share. But what if he asked for the 'profits' of the house as per open market rate?

3) or should i then sell my share to his would-be fiancee (assuming it's possible)? will i be making a loss either way?

4) do i stand a good chance as a single, divorced mother to purchase future bto flat given that we had previously forfeited our first bto flat, and now we had used up all govt grants like proximity housing grant for our current resale flat and am no longer eligible for future grants?

5) what are the available housing options/ schemes and assistance for single, divorced mothers?