What do these dreams mean? And should I tell him how I feel?

Honey, by being "just friends", that is all he wants to be is that and only that and nothing more, you have to move on, he has, and you have to accept that, get active with your friends, and remember why you broke up in the first place, it is normal to grieve, and you now have to go through the process of "healing", and it will take time, but you will get through it, and you also need closure, keep yourself active, hang out with friends, and do things that interest you, and once you do that, you will heal and you will enjoy your life a lot better without him.