How do you know if your addicted to ecstasy?

I don't think i have a problem - I mean the drug makes you feel good (colors, people, and ideas are so beautiful and eye-opening) and there's no research saying it does damage to the brain (other than depleting your serotonin levels; which you regain) and believe me when I tell you I've done extensive research on MDMA's effects. But I get the shakes (and a few times seizures), I have horrible migraines, I waste all the money I get from my job on drugs (though not only buying E - but mosty) and have stolen around 300$ for the pills. Lately I've reduced my E intake (b/c i get drug tested regularly) but I was up to around 20 pills a week and now can't stop thinking about them and how they make me feel. I last took skittles yesterday and already my head is throbbing - and I'm thinking about buying but I'm a bit scared I'm addicted. You can't become addicted to E can you? And if you can - I'd like other peoples opinions b/c I can't ask anyone close to me, they don't know much about my use - do you think I'm addicted?? Thanks so much.