I haven't been dumped by a text message... But I would feel that if that did happen, that just shows that the pearson that is doing the "breakup" is not matrue enough to do this duty face to face with the pearson that they are invovled in. It couldl also very well be, that the reason of the "dumping by text" is because the pearson that is being dumped, ment nothing to the one that is doing this duty by text messanging!
All I have to say is just to hang in there. No mater how the break up goes, break ups are hard. Especially if you are very much involved with that person. Just hang in there.