[s13driver]

ok here is the problem.. i was driving back home with the everything fine but the next morning when i started the car and step on the clutch, it was as soft as a sponge so i check the fluid level, and find out it is empty, so i trace for leaks around the line and stuff and find out both of the master and slaver cylinder is dead so i replaced them both and bleed them,i used dot 3 fluid btw. after i bleed them i still feel no pressure. after many tries it worked. i drive it arond for couple blocks to make sure it is fine. and no problem so far. but at the same night that i got the thing done. i start the car step on the clutch, it has no pressure again. so i check the fluid level and see if it is at the right level or leaks anywhere. but i haven't found anything wrong with it. then after a while the pedal has pressure again. so i take the car out and drive a little and see what's wrong with it and then it lose pressure again while i m driving...
can anyone tell me what the heck is wrong with this pos ? i'm getting too frustrated with it, finals are coming and i need to use the damn thing everyday to get to school and i can't do a thing with the clutch not working right. any suggestion of fixing it ? thanks in advance. sorry about the bad grammar because i can't concentrate anymore because i have too much bad things happen to me lately.