2001 Ford Escape A lot of problems

I have a 2001 Ford Escape and it has over 154,000 miles on it so its running on its last limb but I have tried to fix every problem that has been noticed. The current problem is that when ever I hit the brakes my car makes this horrible sound that is kind of a vibration noise but much louder but the odd thing is that if im in reverse and hit the brakes the noise does not happen and the noise does not happen when the car is in park either its only when it is in drive. I have just recently fixed an exshaust leak and a power steering fluid leak and now I have this problem and no one seems to know what on earth is wrong with my car?

Oh and also every now and then maybe like once a day my battery light flashes on and then turns off a few minutes later?