Something I never seem to learn

Now that I'm finally recovering, I'm again infatuated with my girlfriend. This entire week while I've been dying to strep, I've been kinda depressed and had somewhat withdrawals from caffeine / my ADHD medication which definitely wasn't helping. Because of that, and because I was feeling nothing but depressed feelings like exhaustion or numbness, I automatically try to figure out what's causing these feelings. And so I get in my head and think about what's happening in life and I scare myself by thinking it's because I am now in a relationship. But no, it's because I'm sick and have been bedridden for a week. It's never that bad.