Q.How do you save a potted plant that got too much rain
I have a Yellow Bell in a large pot. We had several days with heavy rain. I poured off the water that was standing in the pot but the soil is saturated.
Let it dry out some before taking up watering again. You did the right thing by pouring off excess water. Can you take it under cover so it doesn't get more rain for a few days?
If you think it is a problem and it isn't drying out fast enough, a fan on low speed can help with air movement and drying.
Check soil moisture with your fingers, or a soil moisture meter is a beautiful tool. Wait to water until the meter shows in the lower moist range.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm