I’m a beginner cross-country rider. My bike is semi-suspended. Using clipless shoes for the first time took down my confidence while going down the mountain ( it really helped while ascending it); I couldn’t handle the rocky terrain at my usual high pace, so I lowered my speed and still fell down 3 times (haven’t fallen off a bike in years!). What does it take to get used to clipless?
How do you use clipless pedals with confidence? It takes practice. Once you get used to them and then get used to getting in and out of them, you’ll have the confidence to go faster knowing you can easily pull your foot out when needed.
This article should help a lot: Clipping in: Easy as 1, 2, 3 - 3 simple steps to help with the clipping in learning curve. Give it a go, it will transform your riding!
With your MTB SPD pedals you will have a tension screw to adjust how hard the pedal holds the shoe. You should wind them right down so they release easy. Run them like this for a few rides and slowly turn up the tension.
The problem you are having is, without clips you are used to putting your inside foot down around corners. You need to re-learn how to ride and gain confidence in your equipment and skills to be able to corner at high speed without putting your foot down.
Hope this helps