Has it been in the same pot for a while? It may simply be needing a feed. For starters you could use a foliar feed - dissolve soluble plant food (eg Miracle grow or similar) and spray the leaves. Not the best way with bay as the leaves are shiny but its quick if it works)! Anyway after that just water some into the pot.

How long have you had it?
It may need potting on into a larger container with fresh compost, or you might be able to top dress it by removing the top layer of compost and replacing it with fresh.
(If you are gardening in the UK it would be useful to change your country to UK on your profile, adding your county too as it makes giving appropriate advice easier)

Re watering - bay is pretty tolerant normally but it survives being dry very well. Only water when the compost is dry. Mine is on a south facing patio and has not been watered all winter. When you do water it give plenty and then wait until its dry. It sounds as though you may well be overwatering.

Too much watering will wash away any nutrients in the soil and denude the roots of oxygen. I would give it a feed with something like Osmacote slow release granules or Vitax Q4 pellets and cut back on the watering. Also be aware that even though bay trees are evergreen, they will also lose leaves as a matter of course.