Hello and welcome to BW forums
Great advice and useful links already given (well worth checking those out)
I just wanted to mention that the day could be a bit more even. Looks like maybe 2 hours awake in the morning then a nap 9-11 but then only 1 hour awake followed by another nap 12 - 2, another single hour before the next nap 3-4 but then possibly 3hrs before bed time. You didn't say when WU (morning wake up) and BT (bed time) was so I am making guesses on those. It could be that you are struggling at BT because he is OT (over tired) with the 3hrs A time which is too long for him, OT babies tend not to go to sleep very well.
A more suitable routine could be:
WU 7
A 2hr
S 9 - 11 (if he repeatedly refuses this nap you might need to look at WU time or extend the first A time a little)
A 2hr
S 1 - 3
A 1hr 45 (shorter because you only want him tired for one sleep cycle or less)
S 4.45 - 5.15 CN
A 1hr 45 (shorter because it is after a CN)
BT 7pm
hope this helps