Mouse shaking, twitching, spazzing out at all times

I need help. I have a mouse collection that love to take care of. In one tank, i have a mouse that is flipping out. About 2 weeks ago it looked sick. Next day, it was very much so. His eyes were crusted shut, his fur was a mess, didnt look well at all. I removed him from the tank to get him away from his girl friends. Then after a few days he looked better. Gave him a few more days by himself then returned him back home. He was very jumpy, acted weird. I thought he was just alone and didnt have anyone with him so he went wild for a little bit (they are white mice by the way). Then a day or so went by and i picked him up, he was still wild, jumpy, etc. Then a day or so later, after i picked him up he was get in these fits of shaking, twitching, head bobbing while i was holding him and a few minutes after i returned him into the cage. He calmed down after. Then it started happening 24/7. He is shaking, going nutts. It looks like he has tourette syndrome or a constant seizure. The wierd thing he is walking around, eating, smelling his girl friends you know what and so on. For all i know he is still making babies. WHAT IS WRONG??? I looked everywhere, ask around and nobody has an answer. Im going to remove him again and put in his own tang, but i dont know what to do. I dont have money for a vet, so maybe there are meds to give him. But i find this very odd. Anyone have any answers.