Is £160k your estimate of the equity due to your h at the time the property was sold? When was it sold and do you have the name of the mortgage lender who obtained a repossession order as it's probable that all of the proceeds of sale was paid to them. Are you 100% certain that whatever part of the proceeds was due to your h has not been paid to him?
Although your name may not have been on the deeds, any equity in the house should be split between you and your h as part of a divorce settlement. In the normal course of events, depending on the age(s) of your dc the probable starting point would be a 70/30 split in your favour but if your h's present incapacity precludes him paying child maintenance and/or spousal support in the near future you may be advised to claim a higher share of the equity.
There's also the question of what pensions rights your h may have accrued if he has been employed at any time prior to becoming incapacitated and whether he has any savings and/or other assets such as vehicles, valuable artworks/objects, jewellery etc that he acquired during your marriage.
Although you have referred to your 'stbxh', it appears that you have not as yet petitioned for divorce. If you can reach agreement with your h in relation to the division of assets, childcare arrangements, etc, you may not need solicitors and can petition for divorce online on payment of court fees at the current rate of £410.
However, before giving any consideration, to proceeding you are best advised to speak to your h's consultant psychiatrist in order to establish that he has mental capacity as a voluntary inpatient who, presumably, entered a pyschiatric unit of his own free will. Out of curiousity, is this a NHS establishment or a private psychiatric facility?
If your h does not have mental capacity matters become more complicated and, although he may be entitled to legal aid, whatever is expended on his behalf may need to be repaid and his costs will rise when/if the Official Solicitor becomes involved.
www.gov.uk/divorce/if-your-husband-or-wife-lacks-mental-capacity
NB. The above information may only apply if you are in England/Wales.
Are you named as your h's next of kin at whatever facility he resides in? Has your h granted power of attorney to you or to another party?
It can be hard to achieve, but you are wise to endeavour to separate the emotion from what is essentially a matter of due process that is required to take place before a decree absolute is granted and your marriage is irrevocably ended by a court of law.
I suspect you have a long backstory to tell and if you are lacking support in rl do please use this thread to offload anonymously as you won't find any shortage of willing hands to hold yours as you continue to do your best to keep everything together for your dc.