Thank you all for the suggestions and support! I'll be sure to try them this week.

I tend to just zone out, thinking about nothing in particular, like a pre-sleeping stage so I don't even notice myself unfocusing until my pen drops or I start thinking about random things. I tend to work in areas with very little distractions. The only thing that could possibly distract me would be my phone which is out of my reach. Due to this, I really am unsure as to what is the cause of my lack of concentration since there isn't a recurrent pattern in terms of what I'm thinking about. In high school when my depression& anxiety weren't as severe, I never had issues such as these.