You will only know if 300 mg helps by trying it but in my case--I couldn't sleep at all on 300 mg a day. I was on 150 mg a day for a long time but have figured out it makes me sleep less. Now I only take 100 mg a day. I can't seem to manage without it (I feel depressed without it) but I think higher doses were making me a bit manic. Did you know there is also a 200 mg a day pill? IMHO, when you go to the doctor, you might want to try increasing to 200 mg a day first. That's just me though--I try to get by with low doses of psych meds whenever possible but I do think they effect everyone differently.