numbness in ankle and leg with tightness

Hello. I noticed about a week and a half ago that the back of my left ankle was numb. I thought no biggy, as I have had lots of blisters back there and figured the nerves or whatever were dead there as a result. Upon further investigation, however, I noticed that the whole back of my lower leg has lost some feeling all the way to the back of my knee. It is just the back of my leg, and I can still feel, it is just numbed a little. I have no other consistent pain except for an occasional tightness, I guess you could say, in my right forearm about halfway up. It seems to tighten or something and then immediately goes away. It doesn't hurt, just feels weird.

A little history, I am 20yr old female. I had back pain about 3 or 4 years ago. Told the muscle on my one side was weak and so the other side was exerting itself too much or something like that. Fixed it up after a couple months of treatment(holistic doctor). I had been working at a horse farm full time for the past year and a half, just quit at the end of September. A lot of physical labor, and it really helped my back, and my body overall become a lot stronger. After I quit, I did pretty much nothing for the next month as I was so exhausted, and my legs felt weak. So I just rested. Still not real physically active, however I plan to start working around my families farm here soon.

No health problems in the family that I am aware of, except for a thyroid disease my Dad was diagnosed with 2 years ago.

The only thing I can find related to this is a nerve problem in the back, but I don't have any back pain which is usually associated with this. I am also not one to panic, which is why I haven't actually gone to the doctor.

Could this just be from lack of physical activity? I would like more input before going to the doctor.

Thanks in advance!