6 weeks of quitting smoking

Hi ... I'm a newbie here, wish to get more advice from friends of this group. I'm 49 yrs old and I start smoking at the age of 18. And this is the first time I quit smoking. I used to smoke about 10 - 15 sticks per day. Reason why I quit smoking is due to I had very bad heartburn attack at July and Dr advice me to quit smoking, so I make up my mind and quit smoking. I just straight away quit smoking , I didn't go by step. Till today I had not smoking for 6 weeks. But now I started to feel uncomfortable I don't know is it the reaction of quitting smoking. I just feel uncomfortable, lost appetite. I don't know is anxiety or panic disorder. I wonder does anyone here ever experience like this before. Hopefully can get some advice from all of you here. Thank you very much