I believe there is not enough hind milk . When the amount pumped out is less than 3 oz. my milk looks watery, too. Maybe you don't mix the ones pumped out in the morning. Instead, mix with that pumped in the office. I spend longer time pumping in the office. More hind milk.
eventhough there are more foremilk, it has a lot of nutriation, don't worry! of course, it is totally diff to water. if you want it to be more creamy, you can drink more soya bean milk, fish soup,..