Strange symptoms, trying to differentiate

Hello. I’ll get right into the facts.
I’m a 20 year old male who, for the past two years, has been experiencing a strange deterioration in health. At first I noticed it as just a loss of tone. I’d always been the gym rat type, and was larger and stronger than your average kid puberty and beyond. In fact, up until about 2 years ago, I’ve been far above average in all strength and endurance activities. So, along with that initial loss of tone, I noticed my face thinned a bit. I didn’t have as much “padding” as I refer to it, mainly temporal/cheeks/ jaw. I didn’t think much of it at the time as it was not truly effecting me. My weight maintained and I felt, for the most part fine. So a year went by as I progressively noticed just a loss of strength and energy. I was not at all worried until I began losing my appetite. At first it was just breakfast, in which I’d just feel naseaus in the morning and would force feed breakfast. Over time, this has progressed to a general discomfort after eating, one in which it feels as though my stomach doesn’t move as fast as it once did. Like there’s a delayed gastric emptying/gut motility. Strangely enough, I’m not at all constipated, so that does mess with the theory it’s a gut motility issue. Lately what’s been bothering me is I’m down to the least musculature I’ve been in years. I’m weaker than ever, smaller than ever, and I have some lumbar lordosis going on. My stomach sort of leans out and my butt has begun to protrude. That’s what initially turned me on to the idea of MD, particularly FSHD. The winging is not extremely apparent, and maybe not there at all as the mind can play tricks on one in my situation, and could just be a result of the overall wasting and my shoulders being thinner than before. My question though, for me to want to actually take this to my doctor, is would one experience this significant of an appetite loss with any sort of MD? Or am I looking at a beast entirely of it’s own.. I can’t find any information regarding MD of any sort involving appetite loss or naseau, etc.
Also, I feel as though I would have progressed further by now. I mean I have a steady gate, no foot drop, no issues whistling or puckering or blowing balloons and I never had. I never experienced any symptoms throughout childhood, and in fact was well above average developmentally. Can’t say anyone in the family has any for of MD based on my current knowledge, but its just something that’s really been in the back of my head lately. I really think I’d rather have all of this be related to some cancer or digestive disease that could either be treated or result in my death. I don’t think I’d be suitable for a lifelong debihlitating illness such as MD.
Any thoughts, suggestions, and ideas would be appreciated.
Thank you