Is performing ghusl for menstruation, without the intention of purification from masturbation, sufficient for complete purification? Are the Hajj and 'Umrah pilgrimages performed by the questioner valid, given that she engaged in masturbation without knowledge of the religious ruling? And is her marriage contract void or valid?

The symptoms mentioned appear to be delusions and hallucinations resulting from obsessive thoughts (waswas). We advise you to supplicate (make du'a) and turn away from them. Ghusl (ritual bath) is only required upon the emission of semen. The intention to remove the major ritual impurity is sufficient for purification from menstruation and janabah (state of major ritual impurity). If you are not certain about the emission of semen, then ghusl is not required. Your prayers and circumambulation (tawaf) are valid if you were not certain of performing these acts of worship while in a state of janabah. Your Hajj and Umrah are valid, and so is your marriage.