Last night, my boyfriend and I were hanging out, and I almost said, "I love you." The words never left my mouth, but he could see that I immediately stopped talking. He asked me what I was about to say. I said it was not a big deal and nothing that should be said at the moment. Because the two of us are very open with each other, he found it very alarming that I wouldn't share what I was thinking. I told him that we would be best if this wasn't said and we move on entirely from it. However, now he's feeling like maybe I did something wrong that I'm not confessing to. I tried to explain that it's not a bad thing, just within our circumstances, it would be bad.
For context, we've only been seeing one another for about 3 months. I think it almost slipped out of me, not that I am actually fully feeling this way. I want to ensure I have a conversation with him to relieve some of the stress he's feeling. I also want to be truthful, so our trust isn't impacted by this. But I also want to make sure I'm not pressuring him or bringing feelings up too soon that I'm not even sure I feel. How should this situation be handled?