Welcome razor
Agoraphobia is a fear of not having control which manifests itself as a fear of the outdoors mostly. Almost all fears and phobias are subs of Agoraphobia because the fear behind them is a fear of not having control of the situation. Even claustrophobia.
Panic attacks happen when some external or internal situation overrides our natural ability to look at it reasonably and make a decision.
Riding a bus you have no control other than that it is your decision to be there. Car, train, subway, boat or plane, they are all the same. A fear of bridges and heights too.
What control boils down to is the difference between having to and wanting to. "Wanting to" gives you back control.
"Having to" sends your mind racing through all the reasons you don't want to. Or can't. And none of those reasons are realistic. They just seem so. But they create fear.
For those of us who use "want to" it works. It take repetition to get it to override "have to". A "want to" mantra at first works as a distraction to keep your mind on what you are doing and keep control with you. And "I won" is the reward for your first success even if it is partial or small. Avoid any mantras or thoughts that have any relationship to "have to" and you can do this. You can be in control and actually enjoy this. Besides you have a reason and a goal.
"have to" only works for little grey mice who have a fear of letting someone down. You don't want to go through life living it based on fear. Leave that to the little grey mice. Live life because you want to and there is so much of it to want.
Davit