symptoms for quitting cigarettes after 17 years

I have small things like pimple inside of my mouth. I have noticed that after quitting cigarettes totally for last 3 months, i had got that. Is it because of constipation or something else serious or it will go later on?

I think you should consult an ENT about these pimples. I don't think you should get these from quiting smoking. I had no problems what so ever when I quit after 8 years of smoking.
Also, if you are having problems with quiting and experiencing desires, you should consult a respiratory care practitioner who are usually more than willing to help people quit with their nutritional and other advice. They work 100%.