I agree with PP - he's too little to wean the nightfeeds yet, if he won't settle he's hungry and needs a feed! Many babies need a nightfeed until they are on solids, only having 1 nightfeed at 3 months is great. There is a big growth spurt at 3 months so he will need extra calories too.
When he wakes at night, if it's been at least 3 hours since his last feed it's better to assume it's hunger, feed him and get him back to sleep ASAP. If he doesn't wake for a feed then that's fine, but if he wakes feed him!
Laura