Depression can occur at any age, and as Rohag said, there doesn't need to be av specific trauma to spark it. Your argument with your father may have upset you, but it is unlikely that it would carry so far into your life.

I see nothing wrong with your getting attatched to the child you babysat. However, you have to be careful with your contact with the child when there may be some instability in the home. Sadly, people will sometimes make false accusations about child abuse or molestation that are not true, simply because they are not happy with the accused. This happens more when the older person is a male and the child a female, but it does happen to both.

Without knowing why your father believes your neighbor is unstable or "insane" its hard to know what is going on.

Right now, the important things is how you are feeling. I would encourage you to take advantage of college counsellors to seek help for your feelings. It sounds like this may be the early onset of depression, and its far better to get it diagnosed and under control early. No one likes to think that they may have an emotional problem, but its worth checking out.

Sam2