I've been shooting once a week all summer using field points, and ive been drilling the bulls-eye everytime. I put broad heads on there and my groups are all over the place. I adjusted my sights and im now back on the bulls-eye for the most part, but my groups aint as tight as before. What could cause this? My bow is a high country with a tru glow sight, whisker biscuit, 31" inch arrows with a 100 grain broad head. By the way, i hate that whisker biscuit its hard on the fletching lol.

what broad head what arrow what poundage ?

Without knowing everything about your set up including your arrow spine and draw weight its hard to determine what your problem is. Out of a properly tuned bow your FTs and BHs should hit the same point of impact. Sometimes just a minor move (1/32" or less) of the rest could be all it takes to get your BHs shooting tighter groups. Sometimes if your arrow is under spined slightly there may be no improving your BH groups. Which direction did you have to move your sights to get your BHs on target?
(example: if your BHs were hitting left of your FTs you would have had to move your sights to the left. I would bet now if you shot your FTs they would hit right of the bull. If so, move your rest in ever so slightly and shoot one BH and one FT and see if there was any change. Note when you move your rest, your FTs will also change POI but not as much as your BHs. You will reach a point when they will both hit the same or very close to each other. Then adjust your sights accordingly. If not then you likely have a spine issue.)
But you're right about the Whisker Biscuit. My suggestion would be to get another rest. Preferably a drop away.

Im shooting 31 inch Terminator 6075 with 100 grain muzzy broadheads. My bow is set at 65 pounds. My field tips were hitting the bulls eye everytime, but when i shot the broad heads they hit WAY low. I adjusted the sights and got the arrow hitting a few inches to the left of the bulls eye which is strange because when i miss with the field tips I always tend to hit slightly to the right. I again adjusted the sights and i can now get the broad heads to hit a grapfruit sized spot.
This bow is an old high country i bought at a pawn shop ten years ago. The string is about six years old, has a tube on the peep sight.

Your bow and arrows are not tuned. You need to get them tuned.

This is an excellent reference: Easton Tuning Guide

First off and far most, get rid of the WB. Move to a dop-away rest and stiffer arrows. The WB is robbing you of fps, the stiffer spinned arrow will also help as well. Just my opinion & recent experience!

And when you do get your rest get it at a pro shop and have them look at your bow. It is also possible that your cams are out of time. And 6 years on a string! You should definitely get new string and cables.
If you don't want to spend the money this year you will have to do some tweaking on your own by moving your rest in accordance with the broadhead tuning method on the previous posters suggestion of the Easton tuning guide.
Your bow is out of tune plain and simple. And I think too that your arrows are underspined.

1. Make sure you have the right arrow shafts.

2. Adjust your rest. Hitting low move your rest up. Shooting left move your rest right. Just centering the rest often does not work.

3. 1000s of people shoot just fine with a whisker biscuit. I shoot a rip cord drop away and like it better but a whisker biscuit will work just fine and has for many years.

4. you should probably get a new string and cables.

The above advice was good (especially about going to a good shop, which will be money well spent), but cam lean is also something to look into.

I used to play the "move the rest from broadhead POI to fieldpoint POI" game, but it often didn't work because cam lean was a much more significant issue.