My toliet has been leaking for a few weeks from the connection line. It seems to be leaking through the upper connection that's a couple inches down from the tank. I tightened everything and overdid it to the point where no water flowed into the tank, so I backed off a little and still leaks. Now, after my shower I'm hearing what I think is air in the line. A high pitched hiss or related noises. I'm wondering if I have a larger problem and should just call a plumber. I'm not very handy. The plumbing is from 1979.