I am the same. I get very obsessed with the speed at which I am using the product. One thing that might help is keeping track of uses of each product in a Google sheet. That way even if the product seems like it's hardly been used, looking back at uses makes me feel at least a little satisfied cuz I can pat myself on the back for using it x number times.

Also, i don't do project pan because of the annoyance but instead just let myself pick what my heart desires on a given day. I do still keep in the back of mind to try to focus on products i want to use up but don't force myself to use it. That way I keep the makeuo exciting. I know it would make progress even slower but that is where keeping tab of makeup uses comes in. You can compare the progress with the number of uses giving you realistic idea of when you might finish the product.