Can anyone tell me what's wrong with me?

Every so often, I get extremely depressed and anxious. During these periods of time, I isolate myself and generally distance myself from everyone. These "episodes" can last anywhere from a few weeks, to months. Some days are so bad that I can't even get out of bed. Today, I was having a particularly awful day but decided to go out anyways because my boyfriend is going to Poland for 3 weeks and is leaving tomorrow. I had some sort of attack and I was shaking uncontrollably. Everytime I tried to look up or talk, I started to cry. I ended up having to go home because I couldn't handle being outside of the house. I proceeded to spend 3 hours crying and staring blankly at my ceiling after that, and now I'm here. Sorry if that was a little strange to add there, but I just wanted to explain what a moderately-bad day is like for me and today was a perfect example. When I'm not having an "episode", I usually feel really good. I'm super outgoing, I love meeting new people, and I love trying new things. These periods can last a while too, sometimes weeks, sometimes months. But I always end up back here in my pit of despair (wow sorry for being dramatic but I don't know how else to explain it :/). These episodes have been plaguing me for as long as I can remember. Sometimes when I'm having an "episode", I get extremely irritable and lash out for no good reason. You could say that I have anger issues, but whatever. However, that used to be a big problem when I was younger, around 7 years old. I used to go to therapy and they never gave me an official diagnosis. I'm now almost 15 and my problems from earlier in life have now manifested into this gigantic mess that I have to live with. Any insights on what may be wrong with me are well appreciated. Also, if you could tell me how to approach my parents about this, that'd be great. I get really anxious when confronting people about anything and my parents aren't observant so they haven't even noticed that anything is up with me :/
Can anyone tell me what's wrong with me?
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