Low Milk supply after returning to work--PLEASE HELP MOMMIES

I am mother of a 3 month old baby boy. We are in UAE, so I did not get 6 months maternity leave. But luckily i got almost 3 months of unpaid leave.

I returned to work last January 29th . Till then I was exclusively breastfeeding my son. But then I switched to formula. He will be on formula in the day time and at night I will be feeding him. But now it seems as though he is not getting enough milk when I am feeding him. He would suck his hands soon after i feed him. Also i need to feed him for hours!! (this was not the case till a few weeks ago). Now I am really worried that my milk supply at night time has gone down!! I know that if we don't feed baby, the supply will drop at that particular time of the day. But I am feeding him at night regularly, so i should be having enough milk at night. Is n't it? Now I am so much worried about it. I have heard of Lactare. Should i try that? Is it available in UAE? But i am worried that after consuming it, I will have leaking breasts at work!

Here we do not have the option to express milk at office!!

Low Milk supply after returning to work--PLEASE HELP MOMMIES