Question about bringing buyer agent after showing is done (OH)

[Tony Win]

Hi Everyone. Total newbie here. 

I called the number on the sign of a property. The listing agent showed me the property. After the showing I tried to work the price. The seller gave a number. I saw many people here have discussed about asking the listing agent for a discount so I did.

I asked the listing agent if it is possible if I don't bring my buyer agent can they give me a discount or rebate. The agent got mad and told me I should not care about how much they earned. And since I didn't bring a buyer agent to the showing, if I bring one now I will have to pay the buyer agent out of my pocket. Since he is an agent and I'm not I guess what he said was true..?

How would you proceed? 

Thank you for your time.