Oh, bless him, he's really keen isn't he?
We had the same for a while, and it does pass as they get more used to crawling. However (I don't want to scare you or make you feel worse now...but) it's the same when they start pulling up to standing. The important thing to ensure sleep doesn't suffer in the long run is how you deal with those wakings. I know it's frustrating and tiring, but you're doing the right thing by going in, lying him down again and resettling him, showing it's sleep time not play time.
Be careful with night feeds though. Are you sure he is hungry 3 times at night, or could he be using the bf to help calm him down and go back to sleep?? If you genuinely think he's hungry, mabe you're right it's the increased activity, or a growth spurt. In that case it'd be better for him, and you, if he caught up the extra feeding in the day. Is he on solids now too? Could you try increasing the calories he gets during the day to try and reduce the night feedings?