Dan, is this a standard aborting time for you, or is it sometimes faster? I'm going to paste some info here that might help you speed it up a bit.
>>>You should have oxygen from a tank/cylinder/cannister, not a concentrator that makes O2 from room air. You should have either a non-rebreather mask or the mask that is made for people with CH, the “Cluster O2 Kit,” which you can buy here: http://www.clusterheadaches.com/ccp8/.
The flow rate should be sufficient that the reservoir bag on your mask is always full when you are ready to inhale using a forceful breathing strategy. For some people, this is 15 liters per minute (lpm); for others it can be higher. Since medical O2 suppliers generally won’t provide a regulator that goes higher than 15 lpm, you might have to get your own regulator. More about regulators below.
You want to have at least two tanks: one large one for home and one smaller one that you can take in the car, to the office, etc.
Batch has recommended what he refers to as a “redneck” approach, in which hyperventilating with room air is alternated with using pure O2. Read more about that here: https://clusterbusters.org/forums/topic/4919-batchs-hyperventilation-red-neck-bag/
If you get a standard non-rebreather mask, there will probably be at least one little circle of small holes in it with no gasket behind it. Tape over that circle or cover it with your thumb when you inhale. Be sure you are pressing the mask firmly to your face; don't use the strap to hold it on (cut the strap). Be sure you are getting a good seal, particularly if you have facial hair. You want to be inhaling pure O2 from your mask, with no room air getting in. Cutting the strap will allow the mask to fall off if you fall asleep, so you don’t continue breathing O2.
Stay on the O2 for 5-10 minutes after you have aborted the attack. For many people, this holds off future attacks.
Many people find that drinking caffeine or some kind of energy beverage as they start on the O2 significantly improves their abort time. More on caffeine/energy beverages below.
People find different ways of breathing that work best for them. I have mentioned Batch’s suggested hyperventilation strategy as one example. In general, you should be inhaling deeply as you begin, holding the air in your lungs for a second or two, and then deeply exhaling, to the extent of doing or nearly doing a "crunch" to force out as much air from your lungs as possible. Looking down toward your feet as you use the O2 has been shown to help with aborts.
Regulators. The oxygen should be flowing into the reservoir bag on your mask at such a rate that you do not have to pause before your next inhale. 15 lpm doesn’t do that for everyone, so they buy different regulators. NOTE that medical O2 tanks take different types of regulators. The smaller tanks use CGA 870 regulators and the larger tanks use CGA 540 regulators (all welding O2 tanks, of any size, take CGA 540 regulators). You can buy higher-flow medical regulators of both types online at amazon, EBay, and elsewhere.
Many people use welding regulators (which, as I have said, will only fit on larger medical tanks). These allow very high flows, and can be adjusted for the optimal flow rate for you. You also can find these at many places, including amazon and EBay. You can get them at welding supply stores, too, but they are likely to be much more expensive. You should be able to find a very acceptable one for about $40 or less. If you buy one, try to be sure that it comes with a barbed valve that will hold your mask tubing. You can also buy a very inexpensive barbed adapter at many hardware stores or online. (Some people have gotten mask tubing onto the non-barbed fitting that is standard for the welding reg -- I'm just not very "handy" in that way.) Also, be aware that unlike a medical regulator, a welding regulator has no lpm settings or gauge. So you have to fiddle with it a little to get the flow rate you want. This becomes very easy very quickly.
One other thing you'll need if you buy a CGA 540 regulator: a large adjustable wrench to tighten the regulator onto the tank.
A demand valve system supplies oxygen only when you inhale (or sometimes when you press a button to release the O2). People who have these swear by them: as much O2 as you need whenever you need it. They can sometimes be found on EBay. There are other sources for them, but I’m not sure what they are. Maybe someone will add that information.