Widowed first-time homebuyer going to closing without cash reserves very soon, advice?

Sorry for the horrific title, but my situation is confusing and I’m trying to be as smart as possible about a very constrained situation, almost none of which is my doing. (Essentially, the loss of my reserves and the debt portion are circumstances brought in by my family members.)

I am about to go to closing to buy the house I live in, which I can only do because it has an apartment I can rent out (I need to paint it and do minor repairs).

This transaction is contentious, and I am buying the house from a family member. Because of their bad decisions, I have house-related debt on credit cards, and it was supposed to be resolved in the closing but was not. That circumstance wiped out my cash reserves — which were modest. I am young to be a widow, and consequently will have one income forever.

With respect to debt, I use YNAB and NEVER spend unbudgeted money. I am not a person who uses credit cards without pre-budgeting, so I’m not worried about creating debt. There is no chance I will have issues with credit card debt because I don’t use them that way.

Obviously, this situation isn’t ideal, but it’s the best path available to me – I never want to remarry, and the rental income can stand in for my husband’s income. A second job wouldn’t work because my day job takes up all my time and I barely have time to do other stuff as it is.

Because I’m buying from a family member, the amount I’m paying is WAY under market/the appraised price, and after closing I should have significant equity on paper. Having this debt that isn’t truly mine has been financially and cognitively draining, and I don’t want to have uncertainty if I can avoid it.

My questions largely involve whether and how I can leverage equity to give me breathing room. I’d really like access to a few months expenses until I have them in cash, and I’d like to consolidate this debt so my cards are back to all being at zero balance/PIF monthly. If possible, I’d like to do very modest repairs for things that have worn out since me and family member moved in about 8 years ago. (If there’s a better approach or ANY insights, please tell me.)

I know my situation is not normal on PF, but I am a financially organized and responsible person who is aware of how risky not having access to liquidity is and how precarious my position will be. None of my current difficulties are a result of bad financial choices, but I also want to really ensure every move I make is going to lead to the security I once had (savings, no debt).

I can give details, but if anyone has ideas about optimizing my situation, please let me know. I’ve been trying to figure this out since the final numbers came in and I feel like I’m not getting anywhere. Thanks, PF.

Edited to add: I’m taking my son to the movies tonight, so I’m not abandoning the discussion but will be out for a few hours (I just got the inbox alert). Thanks.

ETA: FHA loan if it matters.