Fast Travelled and can't get back now

I am on the PC playing this. I am at the point of "confront Dagan at the Koboh observatory."

I was stuck trying to get to the Observatory understructure (I was at the run, jump, climb set to get to the canter tower and I couldn't get past it). So after about 100 tries, I thought I might fast travel to a previous spot (so I could at least play until my frustration level dropped), and now it tells me I am out of the story line to proceed with caution. And I can't fast travel back to anywhere close to the spot I left. All the possible locations at 2,000+ meters away!? After 100+ hours, I didn't want to start all over.

Is there a possible solution to get me back?

Thanks

I attached a snapshot of a walkthrough with the section I can't complete in the top, background.