Try reading before you want to sleep and it will focus your mind and perhaps make your eyes a little tired to help with sleeping.
I don't see how your doctor is going to help you any, though you'll probably get advised to take medication. I think you might benefit from some therapy to see why you worry so much about everything right now that you're making yourself ill. That's your main problem and the one you need to focus on.
Talking to a therapist to help utilize ways to deal with anxiety is a good idea.
You have asthma so your immune system is compromised. It would be wise to get your Vitamin D and Vitamin B12 checked.
D must be at least 50ng or 125nmol
B12 must be at least 500, closer to 1,000
Illness and medications can hinder vitamin/mineral absorption.
Magnesium is needed for many functions and it's very helpful for anxiety. You can even use magnesium lotion or spray topically (spray can sting). Epsom salt foot baths or magnesium chloride Flakes foot bath are relaxing and help reduce anxiety, racing heart and promote sleep.
Other techniques to reduce stress/control anxiety
Deep slow focused breathing
Lavender scent, like essential oil or an herbal balm/cream
Walking or some type of exercise
Pressure points (can look it up online)
I've done everything above.