An obsession is where it becomes detrimental to properly functioning and considered to be more an exaggeration. Well, love, that's probably the same thing, but I guess you can't tell one way or the other and no one can convince you otherwise if it happens to be now your guilty pleasure.
I think many don't know the difference, but that does not mean there is not one and I really think the difference is quite large and not fine at all they do have many similarities which confuses the issue (such as idolizing the one you love/obsess over) but I find that when you obsess you feel you need the person - and though it often has it - love does not require that addictive property I also think obsession is more selfish than love and is based on possession of the person where as pure love values the admired and it's will in obsession the admired becomes an object or a pet - in pure love the admired stays a public beauty I say pure love, of course, cause one can be in love and obsessed at the same time and often people are