RU they do grow out of it, and all of them do so at different times.
T still can't self-settle to sleep, despite us trying everything. He still needs either BF (which tbh I'm feeling ready to stop but he LOVES and will not consider going without) or for DH to rub his back or sometimes rock him still.
Part of our issue is that we just cannot leave him to yell during term time because of DS1, because they share a room. We have tried over the summer and he has just got horribly upset. It is a nightmare, he needs to drop his nap really and then it would be better but he needs to have one about every 2-3 days just to top up and then bedtime goes to hell.
He is up with us now, perfectly cheerful, but just won't sleep.
DS1 on the other hand could just be put to bed from less than a year old. He went through phases of needing someone to sit with him until he fell asleep, but those only lasted a few days, a couple of weeks at the most, and then he was back to settling himself.
The spitting thing I'm sure was horrid for you, but he doesn't understand that it is upsetting for you really - he just knows that he's getting a reaction and so he keeps doing it. Try and ignore. Easier said than done I know!