Help with my son please 😭

My son is 2 next month and I can't get him to eat meals pretty much at all. If I'm lucky he'll eat 1 full meal a day (that's maybe once a week) the rest of the time he will just pick at things. He won't eat anything that he doesn't specifically ask for and I really don't know what to do anymore! When we weaned him he ate all sorts, we went to a restaurant when he was 7 months old and he ate a mixed root and goats cheese tart (like a quiche). I don't know how or even why he got so picky and I can't remember when he started refusing food. I feel like he's small for his age but I'm really small so it could just be genetic. I just don't know what else to do, he basically lives off yogurt. Today he has eaten half a bowl of cereal, a yogurt and about half an egg worth of scrambled egg. It's now his bedtime but I don't want to put him to bed when he's eaten so little and he won't eat anything else (we've made him about 6 meals today). It's starting to really upset me because I feel like I'm failing as a parent due to how little he's eating but I don't know what to do about it anymore. I can't afford to just keep throwing food at him, I just want him to eat at least 2 meals a day with snacks but I can't even get that out of him 😫