basically solids in an infant under a year is just for the experience not for the nutrition. the basic nutritional need for infants is breastmilk! (THANK YOU FOR BREASTFEEDING!!) so just kee nursing, the solids are just to introduce the different flavors and textures, not as much for nutrition. remember that your milk is and always will be the perfect food, it changes as he grows based on his specific growth and health needs. its amazing stuff. its like it just knows what to do.
remember too that being unsatisfied at this age can be a growth spurt (id bet that this is what it is - he has to nurse more often to get more milk to be produced, so keep nursing nursing nursing) or it could be teething or growth development. have patience, just keep nursing on demand this will keep your supply going. even if you think hes not getting anything, chances are he IS, and its still important to keep him nursing no matter how much you think hes getting; demand increases your supply.
contact a local or nearby la leche league. www.LLLI.org. they will be able to give you more information and a ton of support! !:)