Search Results: asking a girl out on facebook

A few years ago, a girl at a neighboring store was super into me, and I thought she was really nice. But my store was closed soon later and after a few months, I asked her on Facebook, since I had to work so much if she'd be interested in being friends with benefits for a while. She said yes.
After a few missed opportunities to get together, because I was working two jobs, she said she wanted to be on a proper date first.
We stopped talking for a few weeks and started again, and she kept telling me how after a few times she wanted to try sex with whipped cream and chocolate syrup and asked to meet her one night do we could start.
After talking for a bit, I kissed her to get the ball rolling, and she said she changed her mind and still wanted a date, but kept grabbing me. Then we kissed again, and she said date first.
We've been on and off conversation over the year, and we recently started talking again, because she picked up a second job too.
Since we're both so busy, if I ask again, would it actually become a real friends with benefits?

OK, here it goes.

I matched with a girl on Tinder a while ago. She seemed like a normal, down to earth girl, we had a few things in common. I wouldn't say I was in love with her personality, or it was 100% match - not by a long shot. But I saw potential.

This was the picture she submitted to Tinder:

After talking a while, we decided to exchange facebook accounts.
When I looked at her profile, turned out she looks more like this:

Now, I am not exactly the most handsome guy around. But for one, I feel deceived. The picture she submitted to Tinder looks literally nothing like her. Which I guess I could have expected... But I did not.
And I really want to avoid sounding like an asshole, but let's just say I don't find her in the least bit attractive. I don't want to criticize her appearance, because I already feel horrible about the situation, but you get the drift.
And I will be honest, appearance and physical attraction IS relevant to me. If this was a one night stand, maybe. But she is looking for a long term relationship, and I don't want that with her. There's a zero percent chance of this working out.

The problem is that I foolishly agreed to a date at a non-specified time on the weekend. I could probably tell her some bullshit about not being able to make it, but that doesn't solve the issue, just postpones it.

Right now I see three options: Either I
-tell her as it is that this is not going to work out and that I am not attracted to her
-lie that I have something going on with someone else
-or ghost her.

I know probably the best course of action is to just tell her. But frankly, it sucks, and I am probably looking for some encouragement, or understanding. I am not experienced with these kinds of situations, this is pretty new to me.

So what would you guys do?

For the record, I am asking this anonymously because I don't like talking about my private life with people knowing who I am.