Welcome back..and I am glad you came back because we all want the best for your horse-and that will give you the best experience.
You NEED a full vet work up.
Sometimes spending more up front and fixing what is really wrong beats the hades out of chasing what might be wrong and throwing money at it. New Bolton is a great choice.
And they most certainly do embrace alternative therapies from nutraceuticals to pharmaceuticals (sp?) to accupuncture to chiro and massage therapy. BUT you gotta know what is wrong.
Spend the money, find out what is really wrong. You owe it to that horse who entrusted it's life and well being to YOU. It is like being a MOM. They have only us to decide on their behalf-act like MOM in that for them, there is nobody else to do that for them. Just you.
When opportunity knocks it's wearing overalls and looks like work.