Try Window > Reset Windows to Factory Settings
If I had to guess, you had a model left open, and when SQL Dev re-opened, it restored the model and you see the modeler toolbar...but it'd be like 15 icons, not 90.
A screenshot would help to solve your mystery.
I've never used the data modeller and now every time I open sqldeveloper the data modeling toolbar is there instead of my usual sql worksheet toolbar.
From the menu when I deselect the main toolbar the modelling toolbar disappears and when I select the code editor, properties, structure, database navigator toolbars nothing appears! This is nuts
Time for a reinstall
Okay redownloaded sqldeveloper and restarted and the same thing happened....toolbars haywire. So obviously there were some configuration files hiding in my system. So eventually found them here ...
...deleted them and I'm now back to my usual interface. How this happened in the first place I've no idea!?
So the Reset Windows thing didn't work?