Yet another CGT question - sorry

[dbullen]

Hi everyone,
I'm really sorry to be asking such a basic question as "how much CGT will I have to pay", but I promise I have been Googling this for ages, and I keep seeing contradictory information (for example some people say that Private Letting Relief is only available if you first live in a property and then rent it out, while others say it doesn't matter when you live in it....). Maybe the rules changed at some point and some of the info I'm reading is old?
Anyway if anyone can help with this, great. If not sorry for troubling you.
House bought June 2000 for £38,500
Rented it from the start - never lived there.
Proposing to sell now for £90,000
So the gross profit is £51,500.
As I understand it I would get 25% taper relief having owned it for 7 years, giving a tapered profit of £38,625, so after my personal allowance of £9,200, the remaining £29,425 would be taxable.
I earn around £30,000 so I'm expecting to pay 22% on £4,600 and 40% on the remaining £24,825 so the total tax bill will be around £10,942.
Is that correct?
Next question, if I was to move into the house for 6 months - and I understand this means really move in, not pretend - I would get still get the personal allowance of £9,200 and the 25% taper relief, plus 3 of the 7 years would be private residence relief, so a further reduction of 3/7 from £29,425 down to £16,814.28. Is this OK so far?
Would I then also be entitled to Letting Relief? And if so how much would this be (this is the particular thing that there seems to be conflicting advice on).
I'd appreciate any advice on this, once again sorry it's so basic. Think I've included all the relevant info. Oh, I'm not married.
Thanks in advance,
Dean