

Hoya in distress
My first hoya! Hindu rope. I don't know why it's called that.
Anyway I got this about 10 months ago and I'm absolutely in love with it. It's in a Solo cup because I had to transplant it out of a smaller container about 6 months ago because it was given to me in a clear cup. When I transplanted it 6 months ago, I used orchid soil, so pretty woody rough stuff. That's what I read on the internet to do.
But now as you can see it's got some yellowing leaves! I thought it was just one leaf last week and so I picked it off figuring maybe an unhealthy leaf isn't good to keep on the plant.
I so love this little guy and I just want to make sure it's so happy! What do I do?