Routine is so essential for babies of his age when it comes to teaching them to sleep through the night. Babies of his age need to know what you expect and when you expect it. A good simple routine will also make your days much easier, as you can plan when to go out, know when to have him sleeping and ensures he is feeding/has solids at the times that are most helpful with sleeping. It will also ensure that you space out feeds from sleep times, which ensures you break the feeding association he has.
I recommend the routines from the excellent book ‘Save Our Sleep’, as are very simple and effective. They are also great when you have other children, as you can more easily plan when to go out, if baby needs to sleep when you get to your destination etc etc.
From your information I see you are doing a feed right before your baby's afternoon sleep. I would cut this out immediately and move it until after his sleep. Using the feed/play/sleep routine is so important to babies being able to settle themselves and not associating feeding with sleeping. I think this feed is probably one of the reasons he is waking so frequently in the night, along with continued night feeding reinforcing the idea that he needs a feed to go back to sleep.
I recommend that you don’t do ‘top-ups’ before he goes into bed, either during the day or at bedtime. This just confuses him and reinforces the association he has between needing a feed to fall asleep.
For a baby of his age, he should not need any feeds during the night. I would recommend however that until he is consistently sleeping through the night, you do a dreamfeed at about 10pm. This means a feed while he is asleep – get him gently out of bed, onto the breast, feed both sides, then back to bed still asleep. Don’t worry about nappy changes or burping. If he wakes during this feed, he needs to go back into bed awake. Doing this feed means you can rest assured he has had enough milk to last the night, then you can use the self settling techniques you choose (see below) to settle him for any waking in the night (which will quickly get less and then stop).