I have seen a master cylinder leak into the booster, thence to the vacuum line. Tough to find that leak.

Thru to the carpet is another tough one.

 

Iam thinking MD mechanic has it right. Tow your car to an experienced brake mechanic. Someone WILL get hurt or die if you do this wrong. Based on your questions you are learning about how to repair cars, brakes are not something you need to mess with.
best of luck
Mike