Hello and welcome to EmpowHer,
First of all, I want to say that age will factor a great deal into what you are experiencing. Your symptoms seem more psychological than physical. However, the physical aspect that may be affecting your moods may be anemia which can be common in young girls. Anemia can cause depression, mood swings, and fatigue as well as other symptoms.
I sense that you feel some paranoia as well, which is evident through your constant "googling" of your symptoms. I do not believe you need to be medicated for this. I believe that paranoia is brought on by a lack of direction in your life. When a person has no set goals or future plans they can hyper-focus on details that are not very important in the long run.
I suggest that you set some short term and long term goals. Then make detailed plans as to how you will fulfill those goals. Your goals can be as simple as finding your happy place 3 times a week. Or as complex as getting closer to your family.
Whatever it is, if you are focusing on a grander and high goal, you will stop being so concerned with every tiny detail of your daily life.
I do not believe you have a crazy, illusive problem. I simply think you need to have a mature mentor in you life who you can trust and talk to whenever you have these overwhelming feelings. i encourage you to seek a therapist or someone you already know who you trust and literally set times and days when you can talk to them about what it on your mind.
Please let me know if you have anything else on your mind.