In all honesty your stats are too low to be doing it quickly. You'll probably get 6min kills, zulrah is profit if you get the kill but if you don't then it's a loss. With your stats you'll need to kill it asap because the longer you take the more food you'll use. Even at 119cb and 96 range and magic there are still times I use up all my food even with a 2minute kill. There isn't anything you can do about being combo'd out but the quicker you do damage the faster it'll die.

http://i.imgur.com/Wfzm8jz.png

1st part is ALWAYS the green form, 2 is when it changes. Open that on your desktop and make it as big as you can. It'll be confusing at first to follow and you will get lost and die because you can't remember what comes next, but the more you do it the easer it'll become. R and M means protect RANGE then switch, so R M R M R M R then it'll move. M means protect MAGE so M R M R M R then it'll change and the pattern will start over and become a new phase. You need to learn all 4 because you wont kill it in time before it starts a new rotation.

But I do suggest getting higher prayer (70) Void range/mage and getting your range and magic up to 85. If you can't afford to chin/ice barage I suggest doing barrows with your stats until you can afford it.

Yes, you can kill zulrah with your stats but they'll be slow kills and slow kills means slow money. Barrows is better money per hour for me and I average 2 minute kills at zulrah. I'm 100% sure you can do it, but even if you get the patterns and pray switching down you'll still die all the time because you have low magic and defence, magic is also 1/4th of your magic defence level. Higher magic level less you'll be hit.