Can somebody please give me some guidance as to where I am going wrong with this woe.

I started this in February 2001 at 238 lbs and got down to 210 relatively easy over six months or so. Since then, nothing! I lose and gain the same 2/3 pounds.

The following is what I am eating:

B: Usually a large frankfurter when I am on the run to work! or bacon and eggs at the weekend.
L: 2 chicken breasts with salad and mayonnaise.
D: either 1 chicken breast with vegetables/lamb chops with veg/steak or gammon steak with eggs.

I usually have sugar free jelly with cream at weekends when I also indulge in my only cups of coffee - 2/3 cups with cream.

Also, sometimes have sugar free polo mints.

I drink at least 3 litres of water a day and am 5'2" tall.

Any ideas?

Any help would be greatly appreciated as I do not want to change to a low fat diet but feel I may have to at this rate.