You haven't messed up yet. You now have an excellent opportunity, research everything you can about companyname and the owner you talked to. Then get yourself on a plane to their offices with everything you have about your company, turn up and ask if you can take the owner to lunch / dinner and pitch him your company. Explain in simple terms that you don't have the cash to change at this late stage, that either you can find an accommodation between both your companies or your company fails. Make an offer of say 5% equity and a link to companyname on your homepage for an agreement not to sue for trademark infringement, I would expect him to make counteroffer, you counter that with something a bit less plus a capital investment of X, negotiate until you have a deal that works for both of you and if you can't, be prepared to walk away, if companyname and your mycompanyname are in the same line of business then you could always pitch yourself as an employee of companyname to the owner.