Don't kid yourself - seafood is high in natural sugar, and is no healthier for you than meat. The only exception would be oily fish (such as herring, mackerel or salmon) which, providing it's wild, is full of useful Omega 3 oils. You need to loosen up a little and eat more different kinds of things. Unless you have a religious objection to chicken and pork, in which case, too bad.
How about an omelette? Healthy and delicious. It has been established that the cholesterol in eggs does not enter the human bloodstream and clog up the arteries, so any worries you have about cholesterol can go out the window. Eggs are cheap (although you should get free range organic ones if possible) and if you grate a little good cheese into the omelette, or add a handful of chopped fresh herbs such as flat leaf parsley, chervil, coriander (cilantro to Yanks), thyme leaf and/or sage, you have a fabulously tasty, high-protein, low-carb meal. It also takes about four minutes to cook a three-egg omelette, so it's quick.
Why do you eat beef but not chicken or pork? Chicken's better for you and pork is more interesting. I personally like beef, but I don't eat it very often.