Hello I have gone through your question and understood your concern. You have some chronic diseases and for this reason you should be careful with the treatement of each condition. There are a lot of conditions that can cause breathing difficulty. In your case the culpit can be hypertension,cold,the enlarged thyroid or even stress or panic attacs before surgery. Your pulse is Ok ,but you have high sistoloc blood pressure and this condition may need treatement as soon as possible. Anyway,my advice for you is:Try to stay calm and contact your treating doctor without delay. The troubles with your breathing and your hypertension should be monitored and the follow up with your doctor is very important for you in this moment because you will have a surgery soon. So,don t be worried ,try to manage stress and contact you healthcare privider as soon as possible. Hope this is helpful. If you have other doubts,feel free and ask. Take care.