When is a wrong action unlawful (haram)? Is every wrong action unlawful? Is it obligatory to abandon whatever I feel is not right? And how do I distinguish between right and wrong in similar situations?

It is obligatory to refer to specialists. If the majority of them determine that the treatment will clearly cause future harm, then it is not permissible except for those who desire it after being fully informed. If its benefit outweighs its harm, then it is permissible. Many treatments have harms, but it is permissible to use them if their benefit outweighs their harm. If specialists differ, and the majority of them affirm its benefit, and this is the approved approach in your university, then there is no harm upon you in performing it to pass the course.