I've damaged my lower back before whilst deadlifting,destroyed my training for weeks. Like you I couldn't drive or do anything without it suddenly going again, it was agony to the point of making me feel physically sick at times. Anti-inflammatory drugs helped things heal as well as pain killers. It took months until I trusted it again when squatting heavy or doing deads. I never used a belt either,still don't but I have perfected my form now so that I have not injured my back in about 2 years. Lay off heavy lifts for about four to six weeks and then try re-introducing them,slowly building your poundages up. I switched from straight bar deadlifting to trap bar deadlififting and find it much easier to keep strict form because I don't have to worry about getting the bar past my knees on the way back down.