Although pediatricians mean well, they aren't all knowing. You know your child better than anyone on the face of this earth. Go with what you feel is best.
I think what they are trying to do is cut back the formula and give more food...sounds like to me. Having a child just nursing (I nurse) and not eating any solids is okay for a child much older than that. Go with your instinct and feed him. Try a bit more food and see, but of course you don't want to overfeed him either.
As far as making your own 'baby food', it's really much simpler than some think it is. I would get some gallon size ziploc freezer bags and some ice cube trays..maybe about 4. I would buy fresh and fresh frozen veggies that you want your child to eat. (I also used the leftovers from dinner for our baby too.) Let's say one weekend, you cook carrots and green beans. After they are cooked, use a hand mixer to puree the veggies, then spoon into the ice cube trays and put in freezer. They'll freeze in no time and then pop them out and into the ziploc bag. Label what they are and do it again with other veggies. In no time, you'll have a freezer full of 'baby food'. I've had green beans, green peas, carrots, butternut squash (you can get it already pureed in the frozen section in a box at Kroger), sweet potatoes, broccoli, etc. I did this with fruits as well. Once you have a lot of them cooked..you don't have to worry about it after a while and all you have to do is pop one cube or two out of the freezer and warm it up and there it is.
I've actually used leftovers such as mashed potatoes or whatever and threw them in the ice cube tray too. Good luck!