So I basically just wasted my time?

The title says it all.

You wasted your time not by playing that game, but by posting this topic. 

You should be lucky for not losing any rating points at third place. 

if you would lose points you would say you didn't waste your time and would be happy?

As I understand, Riptidejr, you are the Doctor Who (according to your avatar). So, what is the problem? If you wasted your time, just use your Time Machine.

Just Doctor. "Who" is added when you're talking about the TV series. The Doctor is just, "The Doctor"

(Ok, I never was a fan of this TV series. Watched it a few times and found it too naive  In my opinion "The (True) Doctor" is Doctor Gregory House".)

Thing is, I lost to someone who was -1 point from me. But I BEAT someone 100 points ahead? Shouldn't I have gained points?

I've seen the third place player gain points while the 2nd place player lost them. I don't know how the formula works, whether it's based on relative performance or mere placement.

Doctor who is one of the best series EVER

And ours too. Please understand that nobody cares.

If you'll open the main forum page https://www.chess.com/clubs/forum/4-player-chess you'll see a "sticky" topic "How the rating system works" at the top of the page.

Although you were the lowest rated player, you lost to two people and beat one person. A score of +0 sounds about right. If you were all the same rating, you would lose points equivalent to if you had lost to one person equal to your rating (as one win and one loss would cancel out).