Congratulations on your new arrival!
Yes, an hour and a half to two hours seems frequent, however, keep in mind your baby's stomach is the size of a golf ball and very efficient at using the nutrition given.
My experience is with breast fed babies and it was frequent, but convenient to do so since nutrition was always available, the right temp, etc and no bottles to deal with. Your situation is with formula feeding and is normal. 6 weeks is often a growth spurt and cluster feeding. Feed him on demand, as his body is saying when he is hungry and yes you should feed a hungry baby.
Babies are messy and 2 or 3 burp clothes a day is not unusual. We had a number of cloths and just kept them handy. You will figure what clothes to put on that are the easiest to change and launder. In the summer months he can hang out in just a diaper or a diaper and t-shirt or onesy.
Remember to try new things to make it work for your family. It will be different for each family and with each child. The things we did with our first weren't always the things we did with our second. We did nurse both kids and with the first it had a terrible start, but then I was glad we got through it, as it saved me a ton of sleep, which with a new little one is always at a premium. Keep it in mind for the next one.
Go to the Dr Sears Web site, askdrsears.com and read on his feeding advice, as Dr Sears has never failed me. This is a tough transition and the learning curve is steep with a newborn, but hang in there! It gets better and better.
Is there a mother's group you can attend? I know the hospital we delivered had a weekly group that met for the first year of life and was run by a nurse. Having other mother's around with similar experiences and insights was great.
Also, is hubby helpful or do you have family around that can be of support? Not advice, but support! If someone comes in to hang out with you and can hold, feed and play with baby, it will give you some freedom to regroup.
Good luck!
J.