Feeling lost with solids

My 5 month old (17 lbs, 27 inches) just started solids and seems like he has an insatiable appetite. I'm worried about overfeeding because he finishes everything I give him... I never know when he's full because he will just keep eating forever.
On just formula he was taking 6.5oz every 2-2.5 hours. Now he's taking 5-6oz formula every 3 hours but also having 3 tbsp (prepared) rice cereal morning and night, half a jar of veggies or fruit with lunchtime bottle and the other half jar of veggies with dinnertime bottle. 
Does that seem like a lot? He doesn't spit up. 
We started feeding him this amount of solids the last two days and the last two nights he slept through with no feedings for the first time ever. 
Any insight is appreciated, I feel so lost!