Hi again, I've got to go and feed lo in a min, so won't be on here until tomorrow, I will leave you with a little advice, but obviously hard to completely diagnose without your answers to many questions.
ways to build up your breast supply
Once effective attachment has been achieved the most important thing for you to do is to put your baby to the breast as often as you can for the first 2 days atleast every 2 hours - throughout the night aswell, this will mean waking up your baby, but if your supply is dwindling, it will benefit hugely from a couple of days of feeding often, let your baby feed for aslong as he wants.
Another way of increasing the stimulation to the breasts is to express milk, I know you have tried this and not had much luck but do keep trying have you got an electric pump, these are so much better than the hand ones, the mileda ones are great. Also try massaging the breast while the baby is feeding this can also help to deliver more milk.
I can't really offer advice on whether formula feeds are needed as I don't have your babies birth weight and weight now, but if you have been advised this then I suggest you do this, but always offer both your breast first.
HTH I will check in tomorrow