If you have shot an '06 with no problems, then your splitting headache did not come from the 7mag. The 2 cartridges have similar recoil. Yes, the 7mag may be more with certain weights, but not much noticeably more.
As for a brake, I own several rifles with brakes, and I am now firmly against them. If you don't wear hearing protection when you shoot, then you will definately get a splitting headache afterwards. Heck, your ears would ring for a couple of days.
Yea, at the range, we wear hearing protection and the reduction in recoil is great. However, when you are in the field, you don't wear hearing protection (at least I usually don't). When I shot my rifle with the brake, my ears were in pain. So, now when I shoot guns with brakes while hunting, I HAVE to wear hearing protection. However, if I shoot non-braked guns, then I don't need hearing protection.
Yes, I know that prolonged shooting can damage my hearing, but I am talking about ONE shot at a deer, hog, etc. ONE shot from a non-braked gun is not going to damage my ears. Plus, I NEED and WANT to hear what's going on around me.
Don't get a muzzle brake.
Zachary