I agree, 400 mg is very low. I'm 45 and 200 lbs and I've been using mushrooms (cubensis) for CHs starting in 2011. I've tried various doses during that time to find what works best for me. For me, 500 mg is ineffective for aborting an attack. The lowest dose that has worked for me is 1.5 grams (1500 mg). Although micro-doses have never worked to abort a CH, my regular 2.5g dose is effective in aborting a CH attack probably 70% of the time. When it works, it's very effective, almost miraculous, one second the CH was there and the next, poof, it's gone like it never happened and I'm shadow free. BUT...I've had a couple of occasions where the medicine did nothing to abort an existing CH and the CH remained throughout the treatment, though it does ease the CH a bit during treatment and it has so far always worked for me preventatively.
Because of the abortive inconsistencies I've experienced, I don't use them to try and abort an attack, only as a preventative treatment because I don't want to waste good medicine. 1.5 grams is good for about a month of PF life, I've found, and a solidly active dose of 2.5 grams will push that PF time up. The longest I've gone PF is 7 months after a dose from some mushrooms I obtained that turned out to be on the very potent side. Though the dose was weighed at 2.5 g it felt like 3.5 to 4 grams of what I was normally getting.
Mushrooms are very hygroscopic so the only way to know for sure how much your consuming (mushrooms, not psilo) is to dry your medicine cracker dry with a desiccant (I use DampRid) and pulverize. I obtain my medicine in 2 year multi-dose batches, pulverize them once cracker dry to homogenize the batch, encapsulate at 500 mg per gel cap and then I take a 1.5 g test sample to test the batch potency so I don't have any surprises later. For me the treatment is mentally exhausting (though well worth it) which only becomes more pronounced with stronger doses, and while the extended PF time is nice, I prefer more frequent treatments to a higher dose treatment. 2.5 g typically gives me 3 to 4 PF months before needing another treatment.
As far as going to sleep after taking a psychoactive dose...Good Luck! I'm sure that's possible with 400mg doses, but I've never been able to sleep while actively undertaking a treatment at 2.5 g, way too much going on in my head for that, but if you can sleep....I always wait till I have a free night and subsequent morning. Individual responses to a given dose will vary of course. If you have never before used mushrooms in any capacity I'd recommend 1 to 1.5 g and see where that puts you and then adjust from there.