Generally speaking it can be beneficial to pulse (or take breaks) from most individual herbs. This helps to maintain the effectiveness and safety. However whether it is necessary, the length of time for or between breaks, depends on the herb, the person, the dose and any conditions that the person may have.
It can be hard put blanket rules on herbs in terms of how they will interact each individual, and Valerian can be one of the more ‘tricky’ ones to do this with but that is all part of the beauty and complexity of herbal medicine as well.
It sounds like you have personally found a nice match, and since it seems to be providing you with continued benefit, it is okay for you to continue, knowing the cautions. If anything comes up that is undesired, or you have further questions about a specific situation, it can be so rewarding to consult a herbal practitioner directly and gain some insights on individual health concerns.
If you do wish to speak with a Registered Herbalist, we can also help connect you with someone in your area or online.