Advice

So I'm 17 and went on a date with a guy who's 21. The thing is, I lied saying that I was 18 when I'm actually 17, BUT my birthday is on the 20th of February and I'll be 18 by then. The age of consent where I live is 16 as well. I really like this guy but I feel bad and don't want to keep leading him on or pretending to be a year older than I am. He seems chill but idk how he'd react. We also had sex and smoked together too. What do I do? I hate lying to him or pretending to be someone I'm not

UPDATE: I'm telling him tomorrow when he wakes up