Mary, I took folic acid every day for the first year and then my GI said I didn't need to take it on the day of the injection. I think the reasoning is that it is not effective with the injection but don't think it has any adverse effects.
I sometimes think I don't sleep the night I take the injection but do take it late at night and sleep is somewhat of an issue with me anyway.
Good luck and hope the MTX works for you.