Can someone explain the ending to me?

The ending is you dying and no one remembering you.

Do you mean you want somebody to tell you the ending? If you couldn't get through it, I'm assuming you don't know how it ends.

Or have you seen the ending?

I can take a whack at it an explanation either way...

SPOILERS (kinda obviously)

So, I'm not sure how far you've seen, but I'll do a really, really fast summary of the last bit of the film:

Evelyn finds out her daughter Joy is the Dark Evil and that the "black hole" is supposed to annihilate Joy from existance. Joy has opened herself up to all realities at once and can't take the stress anymore. She feels that, since all things are happening, nothing matters. Joy's real goal, in fact, hasn't been to destroy the universe, but rather to find someone who cna share her fate. She's orchestrated events so that Evelyn is "full open" as well, and consequently might want to join Joy in her search for oblivion.

The finale is when all entities converge: Joy and Evelyn are looking at the bagel hole (I'll explain that if you didn't see the bagel stuff) and simultaneously fighting in one of the realities. Evelyn has adopted a kind of reality-bending "nonviolent" fighting, inspired by Waymond in the film star universe. She, in different worlds, confronts and reconciles with the other major characters - Waymond, Gong-Gong, and Deirdre - and tells Joy that she won't let her go.

There's a lot of back-and-forth, but ultimately Evelyn allows Joy to choose whether to stay or go and Joy chooses to stay, largely because her mother is accepting her and allowing her the choice at all.

The final scene is them all back at the IRS. Evelyn is checking out a bit again, experiencing all universes at once. The difference is that she seems content.

I believe that the message here is to accept change and inevitability while not giving up on the precious things in life and the connections that make our lives mean something. It is a rejection of a bleak nihilism, instead choosing to live in the here-and-now. Because, although all things are possible, what is important are the lives that we have.

It's nicely summed up in the oft-memed moment, "In another life, I could have been happy with you, doing laundry and taxes."