Unknown citrus tree?

Unknown citrus tree?

I bought this little tree at a local flower shop last summer, it was a little damaged and discounted, but I wanted to rescue it. The woman didn't know what it was and the other shop worker was out of town. It had little orange shaped fruits on it, very small but sphere shaped. I broke one open and it was sour, not sweet at all. I was wondering if anyone here could help me identify it so I know what it needs to grow. Here are a couple pictures of it's blooms, strangely the blooms were healthy on Monday, then took a turn and look slightly shriveled today, even though I have kept the soil moist. Any help would be great.
My New ZZ Plant

My New ZZ Plant

The rest of my apartment

The rest of my apartment

My garden doesn’t know it’s fall.

My garden doesn’t know it’s fall.

Plant ID

Plant ID

Ugh, help me!!

Ugh, help me!!

hanging photos in the stairway

hanging photos in the stairway