Oh, YEAH. Explains alot:

CHEMICAL ADDICTION:
Have you ever heard the phrase "it's chemistry". Well, guess what, it could be! When people fall in love their brains create the chemical phenylethylamine (PEA). The chemical is released from the brain and enters the body (gives a whole new meaning to the expression "pea-brained", doesn't it?). The more in love you get–the more chemical your body receives. The chemical is responsible for that thrill and energy we feel when we fall in love. As the chemical levels rise we feel an intensified excitement and euphoria. The more we feel the increase in excitement the more chemical we release. Oh argh! What a vicious cycle!

Some psychological signs of a sudden drop in this chemical would be preoccupation with the person, or the relationship, that created the release of this chemical; obsessive compulsion to regain this person or relationship back into our lives; and increasing despair, guilt, or shame over our inability to stop wanting or needing this person or relationship.

Some symptoms of physical withdrawal:

sweating or rapid pulse
increased hand tremor
insomnia
nausea or vomiting
physical agitation / irritability or easily excited
anxiety / panic
chills and sweating / clammy skin
loss of appetite
cramps and nausea
feeling of jumpiness or nervousness
feeling of shakiness
emotional volatility, rapid emotional changes
depression
fatigue
difficulty with thinking clearly
sensation of feeling the heart beat (palpitations)
headache