'Original' is one of those concepts that is used to allude to variety of things in various contents. Sometimes it has grand albeit ambiguous connotations, such as when it's married with a judgement of aesthetic value (e.g. the use of colour in this painting is original). Or sometimes its as simple meaning one's own authentic work or the first iteration of something.

Your questions are surrounding the latter of the definitions above, which is synonymous novelty (i.e. 'new and different from what has been known before'). As such, diagnosing your questions as an issue with 'novelty' rather 'originality' is an advantageous distinction to make as it focuses the aim.

Looking to researcher called Maria Kronfeldner, she posited that there's two different types of novelty:

1. Historical novelty - Something that is novel to everyone past and present

2. Psychological novelty - Something that is novel to an individual or a group

I think this is a nice way to think about it because it means that whilst a feeling of yours might not be historically novel, it can be psychologically novel. Or whilst your steps in a new place are certainly not the first time anyone has ever stepped there, they are the first time you've stepped there. And that's what should matter really. This somewhat ties in into what mk said about no-one else having your perspective.

It becomes impossible for us to do anything we deem worthwhile if we become infatuated with the desire to be historically novel. Furthermore, merely being 'new and different from what has been known before' has little value unless that newness is in some way useful or progressive. This is why I think 'originality' as a value judgement means a lot more than simply being 'novel' (psychologically or historically), but this probably isn't the right context to delve deeper into that particular discussion.