You are not losing focus and concentration, you are just not helping this skill to improve, you are letting it do decrease.
If you want to keep your focus and concentration, make sure you are exerting this skill, make sure you are doing things that are going to improve your focus and concentration.
What can you do?
Meditate- the art of meditation means that you simply focus on one thing only for a certain period of time, you are strengthening your focus and concentration.
So any other thing and give it your full attention, and to do that you need to start small, just for a few minutes, so that your skill is going to improve over time.
Read- keep your mind active, READING can help you in so many ways, by keeping your brain healthy, strong, and active.
Start small and make small progress daily.
Reconnect with what you really want.
Your deepest desires require no focus or concentration, they come naturally. In fact to the world they look like discipline, but to you you’re just doing what you want.
Start with simple desires. Doesn’t matter if it’s “productive.” That comes on its own. It’s more important that you reconnect with your own desires, the inner voice inside yourself that knows what it wants.
Focus and concentration are something that come naturally when you align with what you want exactly.
You lose focus and concentration as you allow yourself to become over-indulgent of to-do lists and assignments and things that are “important” but are not deeply aligned with your soul.