Can someone quit flipping the light switch?

Sometimes it feels like one moment I'm good and I can see the light, and the next it feels like someone flipped the light switch.
I felt great today, yesterday too. Now for no reason out of no where I feel anxious and overwhelmed. I think it was triggered by me thinking about Marc being gone tonight at the UK basketball game. I'm so happy he's going I just feel anxious. I'm always afraid when he's gone in the evening. I don't know why because the kids and I always do just fine.
So this is where I want to get really frustrated with myself for not being able to just switch the light back on. I know I need to give myself time and that it's not all going to happen overnight... but I wish it could.
I'm going to do the things I need to do still, focus on the kids and what they need today and fight to overcome my anxiety and in the process maybe give myself a little grace.
"I will love You, O Lord, my strength. The Lord is my rock and my fortress and my deliverer; My God, my strength, in whom I will trust; My shield and the horn of my salvation, my stronghold." (Ps 18.1-2)