You have three choices:
1. Make the repairs the buyer is requesting and continue with the sale.
2. Do not make any of the repairs. The buyer at that point can cancel the offer.
3. Have your agent negotiate a compromise. Find out if the buyer will accept an agreement where you are responsible for some of the repairs.

If the repairs are structural in nature, you may have to amend your seller disclosure statements, depending upon your state laws. If this deal is cancelled, the problems with the property could result in buyers avoiding it.

You and your agent will have to sit down together and figure out what is best for you, but some in some form or another, the three choices above are about all you can do. It is sad to say, but it is entirely possible that choice number 1 may be your best choice.

This isn't legal advice, just an outside real estate opinion.