If you start trading these shares too often you could be classed as a trader rather than investor. Then you don't get the CGT discount among other changes to how you account for the shares. You really need to talk to your accountant. You also need to do some reading and learning. Once you master 1+1=2, the rest of the maths is pretty simple. You just need to keep good records and realise that every different share purchase is a new purchase for tax purposes. There is no average purchase price, each parcel you buy is treated as a seperate shareholding even if its a company you already own.
Do some reading and speak with your accountant. If you don't understand the concepts, record keeping and how to add up the profit I would suggest you shouldn't be trading. If your understanding is as poor as it sounds I would suggest your approach is more akin to gambling than investing.
