I majored in psychology, as i found it both easy & fascinating! I hoped that I could figure out my family, but was still largely unaware of my own problems. Thank goodness!!! Otherwise, I probably would have gone haywire trying to do papers galore on my own psyche!
I don't think that it's wrong to apply some of what you're learning to your own life. Heck, that's a human thing to do! The thing NOT to do is to focus on your own problems, disengaging with the rest of things or ignoring other key factors to receiving proper diagnoses. Even professional doctors can't diagnose themselves properly, due to our own perspectives being in the way at times. We may get it right sometimes, but not always! So, it's best to get another professional to give their diagnosis and guidance for treatment.
Very best wishes to you!!