Completely unexplained tendinosis + tendinitis on another foot. (NOT physically active)

I (26 F, obese at 330 lbs w/ loose skin) knocked my achilles under a couch during last halloween's party and I've had chronic pain since, some days are better than others but I always have a stiffness and an average of 5/10 pain in the mornings before all becomes good. Mostly the same since it happened 9 months ago.

More recently, and that one baffles me, I developped tendinitis on my other achilles for what seems to be no reason! I am NOT physically active and am sedentary, in fact the only exercise I do is things like errands or sitting on a swing. Every time I do a slight bit of exercise, my whole body acreams in pain so it's a vicious cycle... but the tendinitis on that foot's a new one.

Both tendons present the same. Stiff, aching pain close to the heel, without a visible inflammation spot from a spur. Standing still for about a minute or two takes care of 90% of the pain. Some days are a 4/10, some are a 6/10 in pain.

My mom's convinced that almost all my problems come from obesity and keeps convincing me to get a gastric bypass. As exhausting as she is about it, is obesity genuinely a potential cause for my achilles' issues? I would love to go to the doctor but my mom would look into Dr. Google (the same kind that she knocks me down from using...) before going to the ER because I'm fat.