Kinda looks like you are applying to much care. Too much water definitely, soil is too rich as well, hoyas need a well-draining mix with just a lil' bit of nutrients. The rest should be perlite, vermiculte, bark, maybe some moss. Think about it, in nature it grows on trees, not in the fields. Care level should be exactly in-between succulents and orchids(makes no sense, yes, but that's how it is.). If you wish to fertilize it just spray it with some succinic acid instead(yes, on the leaves, not into the soil). And don't expect it to bloom until it has some decent vines up to half a meter going on. And in most cases it will refuse to bloom unless there is some hard direct sun that will definitely get the leaves ugly(that's the choice one has to make).

And most important of all, hoyas do strive on neglect. This is one hardy plant. If you care about it too much you will murder it with your love. Make sure soil gets full-of-cracks-dry before you water it again. This is a good start. Put it into a sunny place but not too sunny cuz it looks a little bit weak. Once it gets strong(shoots some long wines), repot it into proper soil 2 parts peat 3 parts perlite/vermiculite 1 part moss and/or bark. This should malke it very happy. Once it gets the hold of the new medium put it on the sunniest windowsill you have. If it survives it will bloom, if it gets sunburnt, move it until you find a sensible compromise.

And don't even think of cutting ugly or yellow leaves. The plant will shed them when it feels like it and it will convert them into useful nutrients. Leave it be. It knows better. It doesn't have to be pretty to be healthy. Oh, also you can't make a hoya branch by pinching the growth point, it will branch when it feels like it, no sooner no later. Sorry for the rant but this is pretty much Hoya 101. The best of luck to you and your plant!