OCD is an anxiety spectrum disorder which has two primary symptoms- obsession followed by compulsion. Obsessions are commonly observed at thought level and compulsions in one’s behaviour to reduce the anxiety induced by obsessive thoughts.
There are various scientific advances in treatment from options available in oral medication, use of ketamine, neuromodulation and psychotherapy to name a few.
Next Steps
OCD itself is a little rigid disorder to treat and needs higher doses of medication as observed clinically to attain complete functional recovery. T. Sertraline 50 mg is quite a low dose.
Secondly if you have issues tolerating that dose, consult a psychiatrist for alternative options including Fluoxetine, Fluoxamine, Escitalopram etc with or without another augmenting agents.
Health Tips
SSRI like Sertraline or any other names mentioned above can have certain general side effects like gastric upset but they are usually temporary and can subside with antacids.