is there such a thing as love sickness? there's some things I've seen that say that its when you cant eat or sleep etc. but i just want to know if its a real sickness and what the symptoms are?

Love sickness can mean a number of things. Some of it is psychological wherein you work yourself up into a frenzy though that too can cause physical symptoms. Intense sadness or depression (after a breakup maybe) can also cause physical symptoms like those you mentioned. From my reading it looks like the cause of these symptoms is stimulation of the production of stress hormones, including adrenaline which causes what can best be described as similar to a panic or an anxiety attack.

There's also been a few recorded cases of what has romantically been termed 'heart break' in a literal sense. This is when a person has suffered some form of heart attack brought upon or connected to the stress of losing a loved one.