Is what I swore upon considered a vow that obliges me to burn my hand and bathe 10 times, or to fast for three days, given that what I did was by pressing on the area without using my hand?

Watching pornography and practicing masturbation are grave sins, but Allah accepts repentance for them. One must promptly engage in sincere repentance, increase good deeds, supplicate for steadfastness, and have a good opinion of Allah, for despairing of Allah's mercy is among the major sins. If the act leads to the emission of semen, it is considered masturbation, and it does not necessarily require the use of the hand. As for the mentioned oath, it is not a vow, and its expiation is feeding ten poor people, or clothing them, or freeing a slave; if one cannot do that, then fasting for three days. Burning oneself with fire is not permissible. As for punishing oneself, it should be by compelling oneself to strive in lawful acts, not by harming the body. Performing ghusl (ritual bath) ten times consecutively as a punishment is not legislated, due to the harm involved and the detestability of nudity.