How can I overcome the guilt of masturbating in a new place?

Hello doctor,

Three weeks ago we had a problem with water in my apartment, so the owner gave us a second apartment to use the water while they fix the issue. What happened is that day I felt the urge to masturbate but what happened on that day is that I felt ashamed because I felt that I really dirtied the place (because of masturbation) and that the apartment was not mine for me to use it that way. That made me feel shame and telling someone did not solve it. I feel this deep shame whenever I meet anyone because I feel like nobody has ever done this in such a way in such a sequence by sort of taking advantage of the place you were given just because you did not have water which makes what I did bad and I felt if someone knew about it then they would laugh at how I took advantage of this apartment situation, etc. I felt that if I stayed there then maybe it would be something common and no shame would be present. I still have the feeling that because it is scarce that I did something bad and that I am hiding that whenever I speak to any person and that they do not know I did that because it is a taboo.

P.S: I do not have problem with that act, I just feel ashamed from the situation of which it happened that is uncommon and cannot shake off remembering what happened and feeling ashamed as a person in my all to day life. Since I started discovering these sexual traits as a child, I always regarded semen as an unclean thing and tend to overwash after masturbation and regard masturbation as something that everyone hides, therefore, it is bad.

What can I do to get it out of my head and not feel shame anymore? Because the thing that is bothering me is how it happened like nobody gets to get another apartment and do such a thing and that is always messing with my mind. I tried accepting it but it is just not going away and causing me heavy stress and interrupting my everyday life and happiness.