Debilitating Imposter Syndrome

I'm a CPA and I returned to work after an 18 month mat leave. I was promoted upon my return to Manager.

I worked as an SFA for 2.5 years before leaving for mat leave and received my CPA shortly after I started my leave.

I was extremely worried about returning because I feel like my mind isn't as sharp as it used to be. Plus to return to a promotion seemed daunting.

I've been back to work 5 weeks, and some days feel good and others aren't. My old anxieties are creeping back in - getting worried when I look at my phone and don't look "busy", staying "Available" on Teams without going "Away", dreading the sound of Teams call (that is the sound of my nightmares), worrying that every call I have with my manager will be the last.

My manager (who also used to be my manager before mat leave) just made an impromptu call that triggered my anxiety. Turns out it was good news - I'm getting a raise because they felt my compensation wasn't fair considering before mat leave I was one of the best SFAs and my new pay as a Manager didn't reflect that. It's a very small raise, but the sentiment that they pushed back to get me more is amazing to hear.

When will this imposter syndrome stop? How can I make it stop? It's getting too much.