Does anyone ever find they don't have the energy to plan a trip and what did you do?

I'm wanting to go to Japan this year and have already booked off time but I'm just finding that I'm struggling to find the energy to plan and go. I want to go but the planning feels daunting right now.

This is my opportunity to go this year as I will be busy the next couple years after and I don't know when I'll be able to go and get time off if I don't now. Last year I went on a 1 month long trip to Europe where a lot of planning was involved so I wonder if I tired myself out.

Should I push myself and slog through to plan and go? Does it get better or easier or will it make me miserable? Has anyone else experienced this and what have you done?

Edit: Thanks everyone for all your suggestions and tips. I don't feel as overwhelmed now. Trying not to be so rigid and structured in my planning and it's helping.