What you have done is bottom out that bolt in the tapped hole for it and breaking the head off the screw indicates that it is really seized in place. Right now odds are about 50/50 that remainder will snap off at the start of the threads when you try to remove it. That is NOT a good thing, it's quite possible you may end up needing a new engine block. Yeah, this could get that bad.
I would advise that you don't even attempt any shortcuts. Pull the Turbo then the BOV. Then you may have enough to clamp on to give you a ghost of a chance of clamping on it hard enough to get it to move. If you do get it to move DO NOT ATTEMPT TO REMOVE IT IN ONE CONTINUOUS MOTION. I expect that you'll find that there is a tendency to bind up as you unscrew the bolt. If so this means that you will need to WALK the bolt out 1/4 to 1/2 turn at a time. Loosen 1/2 turn and when it starts to bind turn it back and forth until it frees up for that amount of motion. Then proceed another 1/2 turn. Keep doing this until it's out, EVEN IF IT TAKES 2 FULL HOURS TO GET IT OUT. BTW, I've been there done this with a motorcycle that had sat so long every fastener in the engine was corroded in place. Did not snap one single screw.
Note, if you do have to drill out that screw your best option for repair is to plan on changing that tapped hole to an 8mm thread or 6mm helicoil. The way I would approach doing this would to have a machine shop make up a hardened drill bushing out of Oil Hardening with the ID sized for the tap drill being used to repair the hole. Then have them make up a guide plate with all of the mounting holes in place and that hardened bushing press fit at the repair position. BTW my preference is to use a helicoil, they work well and allow you retain the stock thread size. Down side to helicoils is they can come out when you remove a screw. Due to this I suggest using a stud for this hole position if you go with a helicoil.
If you do get the screw out successfully then you'll want to purchase a tap and re-tap the hole, because I expect the threads are probably a bit damaged. I would also suggest that you purchase 3 taps and use a bench grinder to convert those 3 taps into a bottoming tap set by taking two taps and grinding off some of the lead. Then purchase some high strength (grade 8) threaded rod and make and fit a stud to that tapped hole. Because it is possible that those threads are partially sheared from the force you put on them and using those extra threads of that bottom tapped hole with a stud may allow you to restore function to that position. If not going to an 8mm hole may be the best option for repair but you could also get a helicoil set and install a 6mm helicoil. BTW; helicoil sets are NOT cheap but do work well in steel or aluminum and can be purchased from MSC Industrial Supply.
PS; Two notes. One is that we have torque wrenches for a reason and one reason is to avoid mistakes like this. Two, the difference between 22 INCHES and 22mm is approximately 21 Inches. You may wish to edit your first post. You sure had me scratching my head trying to figure out where Ford would use a 22 inch screw on this engine.