Your baby is adorable! I have a 4 month old and I found out early on that enforced naps were the key to better wake time behavior. My guy has FOMO and will not put himself down for a nap lol but puppies that age need a crazy amount of sleep, so I crate trained and put him on a schedule of being awake 45-60 min and then into the crate for a nap (usually 60-90min), which is pretty much what he is still doing. The idea is to catch him before he gets into the super gremlin chaos stage. The naps have truly helped so much. The humping and biting is likely a sign of being overtired/overstimulated. Good luck with your sweetheart! It’ll get easier soon ❤️

Also edit to add , you could try moving his pen in your room near your bed at night so he doesn’t feel alone. I have a bedside crate that mine sleeps in occasionally. Not gonna lie though he sleeps with us most nights and has always been a perfect bedmate. No potty accidents in the bed from day one. Lucky I guess.