You seem to be sick because your face is pale and you cough a lot. You should see a doctor!
Should + main verb
“should” keeps the same form for all subject pronouns:
I, you, he, she….. they should
“Should” is a modal used to give a piece of advice to someone.
Now and future.
To give a piece of advice in the past context, we use the following form:
Should + have + past participle
Example: You should have seen a doctor.