Wow, you've had a LOT going on. The good news is that you have been thoroughly evaluated by your doctor (s). That's great. It should give you some confidence that you are actually physically okay. Sure, doctors can miss something but likely you have major anxiety so all the 'normal things that people have are amplified for you. Have you considered trying to tackle anxiety? It's worth a shot. Do you have times that you are symptom free ever?
What you don't say is, before you had that first tickle in your throat, were you someone who was an anxious person? Did you have phobias? Were you constantly worrying over doing certain things? Anxious people think anxious thoughts, and when this goes on for a long time or is extremely powerful the physiological stuff can follow. Never heard of anyone having as much as you're having, though. What I'd want to know is, did anything happen to trigger that first anxiety attack? You said you used an inhaler -- do you suffer from asthma? Was it a stimulating inhaler? Was it new to you? Were you having trouble breathing at the time? How do you know your blood pressure spiked -- did you get it checked right then and there or did it just feel like that was happening? I ask all of this and I'd ask a lot more, because if you weren't an anxiety sufferer, meaning suffering a diminution in life quality from panic attacks, over worrying things, etc., then even though you've see a ton of docs it still might not be anxiety. It's also uncommon, though I'm sure it happens, to get this disorder at that age. Most of us get it before we're 30 or we don't get it, unless something very traumatic happens that we can't get past. Now, that's just statistics, and you're the only you, but I'm basically getting at, your symptoms other than the panic attacks, if that's what they are, don't sound like anxiety symptoms. You might be one of those folks who have to go to the Mayo Clinic and find out what's really going on. I don't know if that's the case, just suggesting it as a possibility. If you had said you were an anxious person for years and it led to this finally, I'd get it. Most of us who get panic attacks on a chronic basis feel like they came out of nowhere, but when we look back, we can see that they were coming and at some point changed from an episodic thing to a chronic problem. Is that you?