Oh Trishpops, you are doing all the right things please don't feel that you aren't.
I didn't have time to do a lengthy post earlier but my DS2 was just the same at 4 weeks and it is truelly knackering.
I found it hard to adjust because DS1 slept through at 6 weeks and although I was doing everything the same with ds2 he had different ideas!! He feeds on one side for a few mins and then even world war 3 wouldn't wake him.
I used to change his nappy in the night in hopes of waking him but it never did. Took me a while to accept that no matter what we do ultimately newborns call the shots!
Anyway things that have made it easier for me have been feeding lying down and yes I agree it's hard at first to find the right position (I lie ds in the crook of my arm and have a pillow under my elbow to get him at the right level), I stopped doing nappy changes unless he'd pooed and I semi co sleep. So if he's unsettled he stays in with me or if I drift off whilst feeding.
DS2 is 13 weeks now and still wakes a couple of times for food. Can I just say that too that it can all change very quickly. I think it was about 5 weeks and he suddenly went three/four hours between. So on the bright side this time next week your little one may be doing a longer stretch.
Resting in the day is important, even if you can't sleep just lying down with your eyes closed will help your body reenergise.
It's early days, your doing great