I said “I love you” and he didn’t say it back

I feel dumb right now and sad. I’ve been having something with a coworker. We have sex and we both made it clear that we have feelings for each but I’m more open with showing mines than he is with his. We do nice things for each other and we’re always there for each other. When it comes to him showing how he feels it’s one step forward and then immediately it’s one step back. Anyways yesterday I made the mistake of saying that I love him and responded with “I like you too”. At first I laughed it off but now I feel kinda hurt and dumb for even expressing myself and thinking he would feel the same 😞