BAck without baby - google silent reflux, does he have other symptoms? The constant feeding can be a sign as it helps to soothe their bellies (although makes the reflux worse). Persisting with the dummy may help if it's reflux, as will keeping him uprigth as much as possible after feeds. Again, a wrap is also great as it holds them upright and brings them comfort from proximity to you.
Floating in a nice warm bath can also be good, as peanutter suggests.