How long does this take to recover?

How long should I do ERP, so that my brain gets used to it, not to say tired?! I've been working for about three months, but everything still seems vivid in my head, there are even vulgar words in detail... since the sexual topic is both a groinal and a feeling that I want to touch myself. It's mostly related to faces and genitals, so how exactly can that go, if it's emphasized that sex pictures in themselves give that feeling, whoever is in them?

To the people who are in therapy and on their recovery journey when the ocd is tending to die down a bit is it normal for the ocd to keep switching themes until it fully dissipates? Has anyone experienced this?

I’m so scared I’ll be stuck in this forever soo soo scared