I am currently on medical leave and for the past 3 months I've had to pay my rental payments late but they have been paid until December when my job is now only paying me at 60% leave, this has been explained to my landlord but my question is, I've notice that every time I make a deposit into the landlords account he uses the money, can he use rental monies and still file an evicition? Currently for Dec I owe $200 but $1075 has been deposit and some of the money has been used, can an eviction still be filed?

Yes. Your rent is due on x date. If its not paid in full on that date, then late charges and/or eviction can result. However, on a practical standpoint a tenant can bring their account up to date right up to when the sheriff shows at their door to put them out.