Kindly refer to the following link(s):
Suffering from OCD and waswas and takes too long to perform ghusl & Wudu
Wasting water in wudu and ghusl
How to make wudu with a small amount of water?
OCD with Ghusl: How to ensure water reached all hair & body parts?
Must we make sure water has reached every part of our body when making ghusl?