Have I been scammed

Hi all, hope you are healthy and happy.  

I'm seeking advice please. 

Re a property sale contract. 

First I am a ware that if I approach an estate agents to sell my property they will charge 3 to 5% commission.  

In this instance I was approached by an estate agent,  who says they have a client intrested in my property.  

The Client agrees to pay there fees 6,000€ the buyer gives 3000€ to the estate agent to secure the sale while they obtain approval for a mortgage, this 3000€ is placed with my solicitor  once the mortgage is approved more money is paid to my solicitor to make a 10% deposit. 

All is well at this point.

The estate agent then drafts a letter with all the property and my details and all the sales figures . It states at the Notary the following figures will be paid . 

Example 

sale price                    250,000€

Estate agents fee          6000€

Total                            256,000€

These fees to be paid at the Notary 

I believe this was an advisory notice to my solicitor 

But she sent this to me to sign and date. 

Question have I entered into a contract to pay this fee personally even if I don't sell the property.

Can the estate agent have a commission contract that they can claim from either party or both parties in the event of a no sale, as is the case . 

Please only answer this is you have the legal knowledge. Or can advice a good Lawyer. 

Many thanks 

Sam