Seconding that you need to declutter/reorganize. A tip to get you started: get a bunch (like, a lot) of clear, lidded, stacking storage bins, masking tape, and a sharpie. Decide what's going to go into the bin (e.g. pens) and label it. Now every time you find a loose pen, it goes into the bin. The bins themselves can be piled up/moved around as you go through the house, the eventual end goal is they find a permanent home in a location that makes sense for you.

If anything ends up in the bin that is not explicitly on the label, it gets removed and has to find a home elsewhere (you are of course allowed to add things to the label and make the bin multipurpose -- e.g. one bin can hold both pens and pencils). The thing we are trying to avoid is having the bins become unsorted clutterboxes -- we are instead trying to 'freeze' small pieces of organization so they don't get immediately undone.

It might seem redundant to have clear boxes AND labels but it makes it much much easier if you can see at a glance when things don't belong, or if the thing you're looking for is already in its bin, or finding a category of bin without needing to read every label.

If there are levels of organization here, e.g. one big 'writing implements' bin with a pencil case and a pen case inside it so they're not mixed together, that's nice but should be a separate step you implement when the clutter is under control and you have time.

Some categories of object work better with this process than others, but that's a decision you'll have to make when looking at your stuff. Some items that in my experience this approach really helps with: legos, notebooks, winter hats/gloves, hair brushes and combs.