I took a tablet last month to stop my period as I was going

Thank you for the additional information.
The tablet that would have been taken for ten days would have been a progesterone, such as medroxyprogesterone.
The first issue in this situation would be whether you could be pregnant. If you have been sexually active and have not been using birth control, then it is possible that you were pregnant before you took these tablets. The tablets could then cause you to have some bleeding when the tablets were stopped, but you are now having a sensation of not being yourself for the last week associated with nausea because of being pregnant.
It is also possible that these symptoms for the last week are side effects from the tablets that you have been taking. Most hormone tablets can cause these symptoms as side effects. If I knew which tablets were taken, then I could make a better statement of likelihood of these symptoms, but even without knowing the tablets, it can be said that it is possible.
Of course, it is also possible that the symptoms for the last week are unrelated to the tablets and the period, and the most likely cause of such symptoms would be a viral infection.
At this point, the first step would be to get a pregnancy test. If the pregnancy test is negative, then it would be appropriate to take a medicine to ease symptoms. The best that can be taken that is available over the counter would be diphenhydramine, but your doctor can prescribe stronger medicines if the over the counter medicine is not sufficient.
If I can provide any further information, please let me know.