Anxious DS (5) won't leave our side, lurker, help

[beachesandbuckets]

Our DS (5), pfb, has always been a sensitive little lad, slightly anxious, goes through spells of being a nightmare at bedtime, separation anxiety etc.
Recently he has become worse in the daytime, always in our personal space, lurking. If I nip upstairs, he will run after me, he won't go to the loo by himself, etc etc (though understand he is fine at school with this). I have 3 other children, including baby twins, and I am constantly tripping over him as I rush around to get us all up and out for the school run. Normally I am quite understanding, but this morning I lost it with him, and yelled 'get out of my face", "stop lurking" (which I later apologised to him for). Any words of wisdom to avoid it getting worse, stop me losing it again...