This reminds me a bit of being in labor. You may have (in my case) your mom and husband there with you, a great midwife and experienced nurses, but in the end, you are the one who has to do it. And no one else can really feel what you're going through.

And the other realization is, there is no way out but through it.

It may also be like labor in that at some points you think "This is just literally impossible" but you do get through it in the end, and you will too on your own journey.