I'm with Dennis on this one. Take a couple of cleansing breaths and let's look at this in a logical way. Let's eliminate one possible problem at a time.

Here are a few things to look at:
My guess is that with variations of the magnitude you are discussing, it is likely a scope-related problem.

Sometimes scope bases seem to be tight and they are not. If the forward screw mounting your scope base is too long, it can bottom out against the barrel threads and thus seem tight, but it is not really holding the scope base tightly. The answer to this problem is to shorten the front scope base screws.

If your scope is somehow broken, it could cause also cause this type of problem. If you swap out your scope for another scope, even a cheaper one, you should be able to tell if this is the problem.

There are other possible issues, but let's address things one at a time.