I really like the W!

Roman numerals - 1=I, 5=V, 10=X, M=1000 (I don't know the ones for 50, 100, 500)
You generally start with the highest and add on, so I, II, III = 1, 2, 3. V=5 and 6 would be VI (5+1) (starting with the highest). 4 is a bit of a special case - it was originally written as IIII, but because they don't like to repeat the same number more than 4 times, nowadays they generally write it as IV (so first a 1 and then a 5, meaning 1 less than 5).

I'm 13 months, 5 days. I've had almost nightly (and sometimes daily) urges lately. The thing stopping me is that my preferred method requires me to sit at my desk for at least long enough to light a candle and heat something, and I'm generally too scared to do that when I have urges at night. I'm not generally too scared to take a knife from my drawer but cutting in bed without getting blood on the sheets is difficult (and bloody sheets would mean my parents knew what had happened).