The dictionary does not help distinguish among words like hermit, recluse, and solitary. Etymologies help but each word is full of our own personal and subjective impressions. My sense is that hermit embodies a stricter sense of solitude that is conscious, deliberate, with personal justification behind it, if not a body of theory (philosophical or spiritual). A recluse is someone who avoids a public persona. That conveys a more psychological sense to me. A solitary is a kind of informal hermit, not strict in terms of interpersonal relations, not strict in terms of a psychological tendency.
Of course, all these shades of meaning are my own, and only at this moment. None of these perceptions of word meanings may be accurate at all (by what standard, anyway?), or mean the same things to you.