Hi, I Am Visiting Darjeeling In The Next Month. I

Hi, I am visiting Darjeeling in the next month. I have asthma, thalassemia E type so less haemoglobin, mother of a 30 month old child and lactating and taking fulcover tablets regularly. I am from Guwahati. Since, I have asthma, will there be any issues with a high altitude place like Darjeeling? What kind of medical issues I might face due to height? Any emergency medicines I need to carry? And for the child also? I take asthalin also and earlier faced breathlessness when visiting high altitude places like this.
Kindly suggest.