As Onesleeptillwembley wrote, you will need to include both incomes in your SA and you will need your P60.
There is a part of the form for employment and a part for self-employment, so it's very straightforward to complete when you have your figures (i.e. p60, self employed income, expenses etc.) in front of you.
The form does prompt you for which figures to enter in which boxes, but generally you'll be entering gross income (before deductions like tax and expenses) in one part then deductions (tax already paid, expenses etc.) in another.
Any employment or income over the relevant tax year must go in. Yes, put total income, relevant expenses can also be put in, to give you the correct figure. You WILL need your figures from your employment. I suggest you ring the payroll dept.
Confusing myself with self assessment, I was self employed for about 6 months in the time I wasn't employed.
Do I need to add my employment when I.wasn't self employed to my return. I never received a p60 of anything either so I'm quite unsure what my taxable income was. And also would it be taxable income I put on.the forms.as employed or total income. I only earnt £147 profit in the end from self employment.