Hello
I understand your concern.
Pain at right side of chest which goes to back with tendeeness on skin can be because of impending shingles or
herpes zoster infection.
Considering your age and medical history,it is quiet possible you may get shingles due to decreased immunity.
Just look for any red blister or tingling numbness appearing on the affected area.
For now,you can have
analgesic like
acetaminophen 250 mg dose orally for pain and local calamine lotion application for soothing.
If the blisters appear,it confirms shingles and it can be treated by
antiviral drugs like valacyclovir for 7-10 days.
Second possibilty is pleural disease.Does the pain increases on coughing,breathing deeply in?
If so you may get a chest Xray done.
Also get your ECG and
blood lipids done as pain of cardiac origin may present in atypical ways.
Hope this information helps.
Any further query is welcome.