you are not behind
You'd be surprised by how many people are in the same situation as you. Last year, before graduating, I decided to study for a second degree. A lot of worries went through my head: "I'm behind," "I'm going to be the oldest," and so on. Many of these thoughts were just excuses to stay in my comfort zone, but I pushed through.
This week, we were put into tutor groups and had to introduce ourselves. We were all 21+ years old, each with different backgrounds. There was an engineer, someone from linguistics, another who worked before starting university. We all have our own paths, and it doesn’t matter when you start. There is no right time to start, just a start.