Feeling nervous , worried, help!😢

Tanya
Hi there, 
I was hoping one of you breasfeeding mammas could give me some advice.
My baby is 2 months old, and I am exclusively BF. However I started pumping few weeks ago, so I could build a supply since I'm coming back to work in October.
The problem is I don't feel I'm producing enough milk. Sometimes at night I will use a bottle with the milk I pumped, and then I'll pump more. My baby is eating 6 or 8oz before bed, so I'm just scared that I won't have enough milk on the fridge to last the time I'll be at work.
How do I increase my supply? Sometimes I don't pump often cause I feel like I have no milk,my breasts are flat. Should I pump anyway? Or take supplements? 
Thanks for your help- advice!!!
Hopeful Mama!Â