Photo, maaser money is NOT ours no matter what. So giving tzedaka from maaser money should not be too difficult to do. As long as we understand that the 10% that comes off the top of our income for tzedaka does not belong to us.
As far as Hashem making things difficult for us, I never heard of that, but Life happens. Not everything is a test, somethings just happen. But if it is a test from Hashem then it might be something like… will you feel badly that you just gave your money away and now you need it, or will you realize that it was NOT your money and that had nothing to do with what happened to you. Perhaps had you not given the tzedaka something worse could have happened and the fact that you did give the tzedaka, you only had to buy new tires.