Can i have lymphoma if i have one swollen tonsil (been like this 6 months) normal cbc no other swollen lymphnodes ct sinus and xray chest normal bad breath don't use tobacco?

Very unlikely: Lymphoma is highly unlikely. See an ENT specialist if you have not already done so.

Follow up: Enlargement of only one tonsil is unusual in infections and since the tonsil has been enlarged for 6 months it doesn't appear to be an active infection. It is important and reassuring to have it checked by an ENT specialist. I also recommend having it followed by that ENT to make sure that it doesn't increase in size or undergo any changes.

Unlikely: Probably not, based on the limited information you provided; however, significant tonsillar asymmetry is sometimes an indication to rule out lymphoma. A consultation with your doctor or an ENT physician is recommended. They may advise to perform a tonsillectomy.