ISFJs are characterized above all by their desire to serve others, their "need to be needed." In extreme cases, this need is so strong that standard give-and-take relationships are deeply unsatisfying to them; however, most ISFJs find more than enough with which to occupy themselves within the framework of a normal life. (Since ISFJs, like all SJs, are very much bound by the prevailing social conventions, their form of "service" is likely to exclude any elements of moral or political controversy; they specialize in the local, the personal, and the practical.)
ISFJs are often unappreciated, at work, home, and play. Ironically, because they prove over and over that they can be relied on for their loyalty and unstinting, high-quality work, those around them often take them for granted--even take advantage of them. Admittedly, the problem is sometimes aggravated by the ISFJs themselves; for instance, they are notoriously bad at delegating ("If you want it done right, do it yourself"). And although they're hurt by being treated like doormats, they are often unwilling to toot their own horns about their accomplishments because they feel that although they deserve more credit than they're getting, it's somehow wrong to want any sort of reward for doing work (which is supposed to be a virtue in itself).
Same problem as being a Virgo. 
That's about how I figured you'd turn out. 
