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.
There had been a few new additions lately…

There had been a few new additions lately…

Macro – bis

Macro – bis

powdery mildew?

powdery mildew?

Secret Garden!

Secret Garden!

My room!

My room!

First bloom of the year :)

First bloom of the year :)