Hehe, you don't know a long post until you've read one of mine.
The first thing you want to tackle is night sleep, I think. Get him sleeping 10-12 hours at night if you can, with a feeding if needs be. If he's sleeping straight through till morning, great!
As for naps...it sounds like you're going through the normal 4 month nap hiatis. I just went through it. I'm afriad he may take 45 min naps for awhile, depending on how well he adjusts to his new schedule. The most you can do is do your best to extend his naps, keep him as rested as possible, even if he's taking 3-4 45 min naps a day. This is a phase and will pass, but it may take a few weeks to sort itself out. His daytime sleep is developing, and with it, naps often get messed up and there's not much you can do to fix it but ride it out. Use whatever method you use to soothe, being careful not to create any new props (easier said than done, right?).
If pat/shh doesn't work through jolts, just use a hand on his back or shoulder area/tummy and legs/bum area. Don't say anything unless you know it helps soothe. Just pin him to the cot the best you can, but don't apply so much pressure it hurts, obviously. This still may not work, but it's an option you can try.
Just hang in there, believe me it will pass. Feel free to vent if you need to!
*HUGS*
Sonya =P