Sumatriptan pills are nearly worthless. I'm glad they seem to be helping you, but you really want injections or at least the nasal spray. I know that's not good news with your current situation, but it's fact.
You don't have oxygen!?! You need to demand oxygen, or you need to set up your own system using welding oxygen. Oxygen is ESSENTIAL. If you don't have a competent neurologist and won't be seeing one any time soon, you should really consider going the welding route. To repeat: oxygen is ESSENTIAL.
You should have been prescribed a preventive medication, not just an "abortive." Verapamil is the most commonly prescribed preventive.
Read about pharma options so you know what's available. Google [goadsby treatment of cluster headache] for a simple listing.
Plenty of coupons on the internet. For example, www.goodrx.com.
Start the vitamin D3 regimen, which you can read about in the ClusterBuster Files section.
Try drinking an energy shot such as 5-Hour Energy at the first sign of an attack.
Try melatonin at night, starting at 9mg and working up as needed.
Some people find that putting their feet in a tub with water as hot as they can stand helps calm an attack.
Read the list of triggers in the ClusterBuster Files section to be sure you're not creating any unnecessary attacks for yourself.
Consider busting (read the numbered files in that CB Files section).