Is the ghusl I performed after masturbation valid, and do I have to repeat it? What is the ruling on the acts of worship I performed after it? Is it sufficient in ghusl to circulate water over the entire body with the intention, and is it a condition to perform ghusl with a vessel?

You must abandon the forbidden act of masturbation and repent from it.

As for ghusl (ritual bath): A valid ghusl requires intention and making water reach all parts of the body. You must wash the navel, ears, and other various parts of the body; otherwise, the ghusl will not be valid. As for the manner of ghusl, any method by which water covers the entire body is sufficient.

Regarding obsessive thoughts (waswas): You must completely disregard them, as this is the most effective remedy for them.