Drowning will be very painful. You will panic, SI will make you thrash about for anything to grab onto as you sink, your lungs will burn intensely and the 3-4 minutes it takes to pass out will feel incredibly long.
If you're okay with this then go for it. After the 3-4 minutes it can transition to being quite peaceful for some. Not everyone experiences this and the first few minutes will be hell though.
There are more peaceful methods on the forum if you decide this amount of suffering is not something you want.
A still water drowning that involves a blackout dose of a sedative such as alcohol may be more peaceful as this way you would be unconscious by the time drowning occurs and won't feel anything. This can be done in a bathtub with a curved rim to ensure your head slides down into the water upon blackout.