Writer's Fallout Shelter

I know the feeling. I do a lot of planning in my head but it's usually in the middle of the night while laying in the dark so it doesn't see paper or I do plan and put it on paper but it doesn't go much beyond that because my ideas seem to overwhelm me. The only suggestion I can think of when that happens is to start small. I find that when I try to write the story from start to finish in perfect order I get lost or bored or stuck. If I just write the scenes as they come to me then put them together later it works much better for me. That would be my only suggestion is to try looking at small parts rather than the whole story at one time.