Your bow with that arrow is generating about 45 foot pounds of kenitic energy and that plenty enough to drive a good broadhead through a deer. I donate alot of time , especialy this time of year , to a local archery/gun shop and help setup bows and help new shooters get started in the right direction. The first thing guys want to know is "how fast is it" and some of the new bows are able to shoot well in the 300+fps range and some guys will sell a kidney for an extra 10fps.
The bottom line is just like rifles , you can't miss them fast enough to kill them and the faster the bow typicaly the less forgiving they are.
I shoot a fast heavy draw bow that able to shoot in the 330fps range with IBO arrows and have pushed it above 400fps with ultra lite arrows , I have it cranked down but shoot arrows a bit heavier so I loose some speed but the bow is ALOT more quiet and much more forgiving. I also shoot a heavy draw long bow with logs for shafts and it only shoots around 180fps but the deer never know the differance between the two.
If I were you I would stick with what you have , assuming that the arrows are spined correctly for that bow , and shoot a good broadhead , on my slower bow and for guys shooting close to the minimum KE I recomend a good cut on contact head like Steel force or Magnus