What’s wrong with me? [The Plant Says]

In winter, this plant was nothing but bare “woodiness”. Come spring it was the healthiest I’ve ever seen

which I thought was thanks to moving it into the house & placing it near a North facing window, (it was a beautiful mosaic look for such a long time!). I guess because of it’s complete 360 I expected it to come back again because I haven’t changed a thing, (regular watering), except I gave it indoor plant food 2 weeks ago but it was already looking sad.

What’s going on?!
I considered maybe it needs a new pot? I can’t “take it outside” because it’d be fried in this heat :\