Home under contract, came across a financing hiccup!

[Jonathon Nila]

Hey what's up BP! Where do I start? So I have a two home property under contract the hiccup I am experiencing is not being able to get bank financing approval for an FHA loan due to the tax records showing this homes as a single family with a detached two car garage that was converted to a living space 2b1b. Loan limits in my county is 396k asking for 420k on property I would have to come in down payment 24k not including 10k closing costs for a total of 34k. I only have 24k total. I suggested the seller help pay for closing costs so we can close and they refused. due to the listing saying multi family but it was actually single family. Tried getting a co borrower to go conventional route but that did not workout out due to co borrowers job history not lengthy enough. my credit is good just don't have enough funds to close what would you do? Options? Should I counter with the seller about helping with closing costs even though they disagree or walk? I am there second buyer in contract so I wouldn't imagine they want to restart the selling process?