Future plan bomb

We met over 3 years ago in our local pub but were dating other people at the time, he was my forbidden fruit forever out of reach with an 11 year age gap (I was 19 when we met) I didn't think he would date me. We continued to chat and socialise as we often drank in the same local pubs.
Start of this year I was happily single then lockdown 1 happened and he appeared in my DMs in June wishing me a happy birthday and asking how I’ve been. He finally asked me out, I thought OMG finally he wants go out with me, this is it. I was elated. We've been on dates, drank lots of wine, he accidently dropped the L bomb on me. But then he also dropped the future plans on me. He wants children sooner rather than later (in 3 years). He wants to move in and marriage...I don't even think about these things at this point in my life. How do I tell him I think I like the idea of us more than the actual us. Sometimes receiving love is more stressful than giving. I do really like him and we are very compatible but the way he looks at me (he is the human love heart eye emoji) makes me feel guilty.