Greetings Neil - you're welcome here.

These experiences are by no means uncommon. The surrounding field is awash with such 'entities'. They work to enter people's fields, linger there and drain energy. I know that sounds pretty unpleasant, but nevertheless it goes on.

It's important to realise, they can only enter where there is essentially unconsciousness - where one might have a consciousness 'blind spot'.

It definitely sounds like you're becoming very conscious of the 4D field - where they reside. And it sounds like you're beginning to natural intuit the right counteractions.

Key is to accept it is happening; work not to go into fear or panic at all. Just accept that it's there. From the place of acceptance, then be really clear throughout your field that such entities don't belong.

Be also really careful of the 'good' feeling ones. If you find your consciousness beginning to leave your body as a result, then that's not necessarily good at all - because something else can slip in whilst you're vacated. It could be a 'trojan horse'.

So keep accepting, but work to infuse your consciousness throughout your body with the breath. Be really clear in your mind and heart that nothing belongs in your field that doesn't serve your highest good.

You might find this of value...
http://www.openhandweb.org/9_methods_for_dealing_with_Psychic_Energy_At…

Best wishes

Open