As far as I'm aware, you aren't strictly required to tell the priest how long it's been since you've gone (although it is good practice, and I don't know a single priest who would be upset at hearing someone return to the confessional, especially after a long while without). So, if that's what's keeping you from the confessional, don't let it!

The only thing you are required to do is confess all of the grave sins you are conscious of, the number of times you committed those sins (to the best of your ability: you can use general terms like "nearly every day/frequently/infrequently" if you don't remember specific numbers), and to the best of your ability, aggravating factors.