“Mysterious “episodes”?”

Here’s what happens, I call them “episodes”. So usually I noticed it’s about to happen because I feel extremely sleepy, the kind that’s so bad you have to give in, or extremely tired my body feels like a giant is laying on it, or I’d feel really really sick. Either those happen or I could be doing regular stuff throughout my day and then my body does this internal “drop” and I feel this heaviness and I need to sit down or get to the ground because I just feel..fatigued. When I finally get down it’s like my head starts to spin, or hurt, my breathing is labored, my mouth would salivate, I usually just try and keep swallowing but I’ve noticed the salivating is quite annoying, my body is extremely uncomfortable and I can’t talk physically or mentally, not while it’s happening. I get extremely sensitive to light and usually, my eyes are shut the entire time because light hurts the worse while “it’s” happening. I always get to the ground because standing is so unrealistic. I always fear falling. I always think maybe I’m dehydrated or something. I don’t know. It’s confusing. I do get random dizzy spells, vertigo. Often times I can’t stay sitting up and playing my game or watch anything. My body just gives out on me. The fatigue is so hard to bear most days. But I struggle with keeping a daily sleep schedule. I’ve been better at it since January started. It’s hard to explain this to the doctors. They all say anxiety or depression. But I think it’s something else. I can’t explain these things. Or the extreme fatigue that’s so hard to get past. I’d have to pray to God to give me strength. And these “episodes”, it’s like I can feel my heart through my entire body. It’s an intense moment of discomfort that causes all those symptoms at the same time. It lasts for about 15 minutes. And I’m left feeling exhausted, tired, but finally able to talk in my head, but my body is tired. I can finally get up and move when it’s over though. It’s night and day difference when “its” happening, and when “its” finally over. Usually immediately after I’m extremely sensitive to light, especially during it. And I feel pressure in my forehead, sometimes my face tingles too and twitches.