I just wanted to mention that you should consider whether your baby has reflux. One if my friends' babies has it and has the same symptoms... Does he like being in his car seat? It would be worth checking up on the Internet (it's often not diagnosed by HV etc)
Can't really offer much advice I'm afraid but I didn't want you to go unnoticed as it does sound awful. Is the hourly waking a recent thing or has it been going on for a while? If it's been like this for a while then I agree that it might be good to seek help from your GP, if only to rule out things like silent reflux.
If he's previously slept for longer then I would just hope it's a short-lived phase and do whatever you need to do to get through it! My DS was similar for a few weeks and we co-slept every few nights just to enable me to get some sleep. He did still wake frequently like your DS but at least I didn't have to get up.
My DS has improved a bit - a typical night was 2 hourly waking until very recently. He's now 9 months and wakes 3-4 hourly which feels like bliss!
I don't know whether it made any difference but what I tried to do was to leave him in the cot and pat him back to sleep (with white noise sometimes) when possible and try to feed no more than 2-hourly. Then in the last few weeks ivebeen leaving him to cry a bit more so that he can learn to self-settle which does seem to be helping a bit. But your DS is much too little for that...
Oh and I agree that te naps sound normal. My DS is still following that pattern. I wouldn't worry too much about them not being in the cot but if you are keen then try it with the first nap (try 1.5 hours after waking) by rocking/feeding/patting to settle him.
Hoping someone can help me with what to do with my DS who is 5 months. He goes to bed at 6 then wakes after an hour screaming and generally has to be fed or rocked to sleep but continues to wake hourly until morning repeating the feeding / rocking. We use white noise and occasionally he will self settle but is rare and still wakes after an hour. He has crap naps, 3 or 4 a day each between 30- 50 mins. He is in his pram for those but would like to get hom in the cot. When he is awake he is grumpy as he is obviously so tired. I tried co sleeping but he still wakes hourly. He is not teething but I use gel anyway and have given Infacol and calpol but doesn't make a difference. Has been going on for over a month and really would appreciate any advice as how I can help him sleep better as we are both knackered. Thanks