hi Kristy,
first of all, yes, this sounds very normal (unfortunately!). 4 months is a big developmental time, and their sleeping skills seem to go out the window cause they want to practice all their new skills!
this does just mean you have to ride it out. if pat/shh doesn't seem to be working anymore, it's okay to start pu/pd. it does take time for your soothing to take effect, and consistency is a big part of that. you really want to try & avoid any accidental parenting (i.e. rocking to sleep) cause that will set you back.
the other thing i noticed on your schedule is that he seems to have a really long awake time in the morning before his first nap. most babies that age can only go 2 hours at the most before that first nap. it may be that he's going down too late and he's already overtired, and that throws off the rest of the day too.
HTH