There is a Lymphedema Community and can be accessed via the following link though I notice there's not been any activity since December 2016:
http://www.medhelp.org/forums/Lymphedema/show/1178
Lymphedema can be either Primary or Secondary.
Secondary lymphedema is usually caused by removal or damage to the lymph nodes. This can be caused by radiation, cancer. Have you had any of these? Infection or parasite in the lymph nodes can also cause lymphedema. Infection or parasites are most common in tropical and subtropical areas and is more likely to occur in developing countries.
Primary lymphedema is a rare, inherited condition caused by one of several conditions, including Milroy's disease (congenital lymphedema), beginning in infancy; Meige's disease (lymphedema praecox), beginning in puberty or during pregnancy; Late-onset lymphedema (lymphedema tarda), beginning after age 35.
Have you been diagnosed with lymphedema? If not, perhaps that's not your problem...
Unfortunately, many of us just have heavier legs and since we can't "spot reduce", it can be difficult to lose weight in a particular area. My thighs are heavier and I have saddlebags; even when I only weighed 100 lbs, I had them and nothing I did would get rid of them...