Many times we just don't feel like chanting – it's common amongst devotees, despite the number of years we've been engaged in reciting the Holy names.
If we have doubts about chanting, it means we don't feel anything and it's become mechanical or ritualistic….something we do because we have to do it not necessarily because we want to.
“…even if there may be some problems, always try to remain in Krsna consciousness. Do not give up chanting the Hare Krsna mantra simply due to some external difficulties. Under all circumstances you should always chant Hare Krsna Hare Krsna Krsna Krsna Hare Hare, Hare Rama Hare Rama Rama Rama Hare Hare. This will protect you from all danger of being influenced by maya or the material energy.”
Letter to Sudhindra Kisora Raya,
Don’t Stop Chanting