I had a similar issue in January after an AG update and had to quickly pivot to Cursor. I’m back on AG now because the AG usage on the Ultra plan beats Cursor pro by far. I more than tripled the $200/mo cost with overages in a month. Cursor has some great features and many more models, but the costs are super high.
Using your own API Key is an option, but some key features require a cursor subscription
You might want to look as VS Code too - API keys can be used here as well