If you sell the property for £460,000 having paid £330,000 to buy it, you will make a gain of £130,000. Deduct the annual CGT exemption of £11,100 and you are left with a net taxable gain of £118,900. You can reduce the gain by claiming for buying and selling legal fees, stamp duty, survey fees and selling agent fees.
I have calculated an annual rental profit of £8,297 (£20,100 - £6,393 mortage interest - £2,517 service charge, £240 insurance and £2,653 letting agent fee inclusive of VAT). Pro-rata for the period from 6 April 2016 to 10 November (8 months) the profit is £5,531. Add that to your salary and you have an income of £40,531. That means, you will have about £2,469 of the 20% tax band which can used to tax part of the net taxable gain at 18%. So, your CGT will be about £33,045.10 (£2,469 @ 18% + £116,431 @ 28%). It cannot be taxed at more than 28%.
I hope this helps but let me know if you have any further questions.