I started out as a subless BLM also. That was back in 2003/2004 when there was no combat bonus from signet, no FoV buffs, and EP meant "might kick your ass", and EP mobs gave as little as half as much XP as they do now. The food system was also a bit different, not that any NA players had either a clue about food or the gil to buy it. The closest thing to a wiki was my handwritten list of all the spells that each magic vendor sold. Oh, and there were no XP rings. Find or make some sort of cheap food. Even Grilled Hare, which you can make yourself at minimal cost, is better than nothing.Get an XP band. You should have enough CP now to buy one.Use FoV to get more xp, and then use your tabs for FoV regen and refresh. Alternately, you can drink selbina milk for regen. Juice for refresh is an option too, but more expensive.
All that has changed. Don't get me wrong... subless BLM is still going to suck. But you need not be stuck fighting for your life against anything worth more than 15 xp. Do everything that Fynlar said above. In addition: