A customer recently wrote me this email:
"My son is 4 months old and exclusively breastfed. As I suffered from low milk supply and slow weight gain with my first baby and ended up topping him up with formula from 3 months onwards only to have him weaning himself at 8 months old, so I don't to make the same mistakes this time."
Well you've already made the first decision, that you want to breastfeed rather than starting on formula, so now we just have to figure out a way to help. This is actually quite a common question, so you are not alone.
Maybe your milk supply has decreased - you could see your doctor or midwife for a prescription of Domperidone, and there are milk teas available also.
You could try express a little with a breast pump after each feed so that your breasts think that baby is drinking more and so will produce more. This will take a few days for it to build up slowly.
You could also do some breast compressions on your boob while baby is feeding, as this helps the milk to flow and can get baby to feed longer.
Make sure you drink a glass of water after every feed, and also every time that you express too.
And get plenty of rest - though I know how this is nearly impossible when you have a toddler and a newborn baby to look after.
The last thing you want to give the baby at this point is bottles, that will put an end to the breastfeeding if your supply is already low. You could try to offer a few solids like some very runny baby rice "farex" with a spoon. If you do this, give baby as much as he will take without forcing and as frequently as he seems hungry.