J.P.
Hi--
I agree with everyone else--babies do not wean willingly at this young of age--there's definitely something else going on. It could be teething, it could be food allergies, it could be acid reflux, etc. Are there any other symptoms? Like rashes, dark or puffy circles under the eyes, a change in sleep patterns? I went through some rough stuff with my oldest and if you are seeing other changes like these I can walk you through how to deal with it.
Good luck,
J.