I'm feeling lost right now. I could really, really use some help. I currently take 1000mcg of hydroxy B12 and 1600-2400mcg of folinic acid (the only form I tolerate) daily. I also take 300-400mcg of magnesium each day. I have been taking a low-dose B-complex too, although not every day. It only provides 100% of the RDA of each B vitamin, so it's not the megadoses provided by many other complexes. Folate is especially important for me as I'm on a diuretic that can cause dramatically lower levels of folate over long-term use. I've been on it for like 5-6 years. I've been doing much better for some time now. No more neuropathy in my feet, the excruciating collarbone and shoulder pain is gone... However, I feel like my fatigue has been worse for about a month now. And my air hunger has returned with a vengeance. My heart rate also spikes above 100bpm at rest or with mild exertion. Normally it's around 85bpm. I constantly have to yawn and struggle for deep breaths. It's so uncomfortable, and causes headaches and a sore chest. I'm miserable. I only really started experiencing air hunger once I started on B12 years ago. I thought I had solved it with potassium as needed and by taking a proper dose of folinic acid, which I wasn't doing initially (I was just taking B12 alone). This forum helped me learn a lot! But now it seems like even the potassium isn't helping. I can only take three 99mcg tablets before my body seems to think I'm prepping for a colonoscopy! LOL! Ugh. I got my vitamin D levels tested (54) and my ferritin (81). Both seem fine. My thyroid levels are normal as well (and I did a lot of research on what the real normal levels are, not what doctors think they are). I have no clue what to do. Honestly no clue whatsoever. I don't know why this is happening. Should I stop all B12 and folate for a short bit, try upping my doses... Can anyone help me?