给害怕在公共场合讲英语用英文提几条合理的建议

Here are my suggestions:
Aim low (literally and figuratively) at first,by talking to kids perhaps - you would not feel like losing face as much if you screw up with them,but it can still help to build your confidence from the ground up.
Work on becoming "shameless" (only in terms of speaking English in public).
Forget who you are.

首先是要敢说，不能害怕被人嘲笑。
其次自己可以私下多花时间去联系自己的口语和听力，不断提高自己的英语水平。
加油啊，相信你是可以的！