Dee-
If you put too much grain stuff like bread or rice, it will start a hot compost reaction and your bin will start heating up- no good. Also, too much grain gives the worms 'protein poisoning' and they start to become deformed, like tied sausages (eew) and die.
Try to never put more than 1/4 or 1/4 of the food as grain-based scraps. They really love fruit and veggies scraps best, plus teabags and coffee grounds, and ground up eggshells. they also need the FIBER of shredded newspaper and cardboard- the fiber is good and also it keeps more air in the bedding. torn up cardboard egg cartons are a favorite, or brown cardboard box material.

It sounds like you are adding too much water to your bin. Leave the top off during the day. The daylight will keep the worms from trying to escape during the day, then put the lid on at night loosely. If your bin gets too sopping wet the worms will try to escape and the bin will smell bad. There is no way to 'seal' the worms in a bin when they don't like the conditions- and sealing up the lid and airholes just makes things wetter, stinkier, and worse.
Air circulation is your friend.

I drain the rotting scraps in the sink and squeeze the excess liquid out of it before adding to the bin.
If you bin gets too wet you can adding more dry shredded newspaper and mix it in a bit gently, and leave the lid vented open more.