Toddler having nightmares and grinding teeth

I wondered if anyone had any suggestions on how to help my three year old sleep better please...

Over the last few months he's developed a bit of fear about going to bed. We can't get him to settle on his own so end up reading him stories, singing ot sitting next to him until he drops off. Usually it only takes 5-10 mins but he used to be so easy you'd put him to bed then ditch him!

He then wakes in the night at least once and shouts me due to a bad dream or, I think, not wanting to go back to sleep on his own so we end up getting in bed with him until he drops off... again a quick process but I'm knackered!

Finally, he's started grinding his teeth in his sleep to top it off which I think is down to the stress 😢. 

Can anyone help or suggest any things to try? I've read Half a banana before bed may help so I'll try that tonight.

Thank you muchly