Unsold inventory from last year

I started my business in September last year, I've kept all purchased and sold receipts but my record keeping hasn't been efficient enough. I buy and sell computer parts and buy lots of the same model computer and sometimes separate it (e.g. sell the computer separately from the mouse) My problem is I haven't completed the tax return yet and haven't sold all my stock bought from last year. There is no way to link the receipts to which particular product i bought from last year. How do I go about recording all the leftovr stock from last tax year into this tax year? As if I sell them now it will appear as clear profit?

Hi,
Please have a look at the guidance at Business records if you're self-employed.  
You may find there are commerical sofware packages out there, to manage your business accounts, stock contol etc.  
To remain impartial, we cannot suggest any products which you can use for this purpose.  
Please also have a look at Expenses if you're self-employed.
Thank you.