With your grandmother, might be there is a family susceptibility to genetic mental illness. If you are depressed from a partially genetic basis, you may have to deal with depression off and on throughout your life. The plus is, that you seem to sense your moods and have identified your trouble. You also seem savvy enough to know whom you can trust and whom you can't. I think both these things are VERY positive and will help you deal with this. Just think of your depression as a disease, like diabetes. You need to care for yourself and look out for yourself, just as the diabetic would. And, like the diabetic, if you take care of yourself and pay attention to your disease and what treatment you need, you will live a long and productive, mostly happy life. Don't be too hard on yourself--things like the stress you are under will be pulling you down. But you can do things, little things, to please yourself. Take a bubblebath, go for a walk outside, listen to music you like. Take care of yourself, for you--you are worth it! I do believe you will be fine--you have a good start I think.