Ah, those long hours are hard aren't they? You feel you spend longer settling than they do sleeping!
Are you letting him get overtired before putting him to bed? It is much easier to settle them if you catch them when they start to get tired. Look for the staring eyes, red, watery eyes, yawns, blank stares before he gets to the grizzly stage.

I find now that if my DD gets really overtired I have trouble getting her to settle. I wrap her and pat her bottom while either swaying or bouncing on my gym ball till she is calm again then I put her back into her bed.

Are you feeding him to sleep at night but not in the day? Maybe he thinks he needs to feed to sleep everytime. Could you feed him till he is content and "dopey" then put him to bed before he actually goes to sleep? That might help him as he will feel comfy but still awake and learn that going to bed is ok. If he needs to feel close to you, you could put a tshirt of yours down for him to lie on so he gets your scent.

That's all I can think of at present. My other thought was that he is having a 'wonder week' and he will settle better in a week or so. My DD did the same at 5weeks, needing a bit more attention and trouble to settle. He is probably noticing more around him now too so maybe getting overstimulated and tiring easier?

Good luck!