@PetitTorteois
Why do you reply straight away? Wait a bit, a few days.
Eh? Wait a few DAYS (every time) before replying to a text or message?
Why? 
I would be kicking to the kerb, any friend of mine who took a few DAYS to respond to a message every time. I mean, do you just look at a message on your phone, and think 'hmmm, it's Monday afternoon; I will wait til Friday morning to answer it?' I mean WTAF? 
I don't expect people to drop everything and text me back immediately, but I think expecting a response the same day is reasonable! (Unless it's after 6pm, then anytime the next day is fine.)
I find it very intimidating when people reply instantly. Puts me off writing anything back.
You sound like very hard work. You find it intimidating when someone answers a message quickly?
Maybe they are answering quickly because they've been waiting 4 days for your response from their last message to you!!
@Cazza17 YANBU. I would be kicking this so-called friend to the kerb. Waiting 10 days to text back is a pisstake. Then again, I reckon I would have phoned her 3 or 4 days after not getting an answer back, to see if she's OK/if she got my text.