Flatulence, Headache, Constipation Post Mirtaz, Zicam For Insomnia. Remedy Without Side Effects?

i am suffering from insomnia frm past 6 months.....changed doctors thrice.... dont know which is better....first dr prescribed inderal 40 mg and anxit .25 mg ...worked well fr one month....but when stopped am back to same problem.....second gave inderal 10 mg twice and lonazep 1 mg in d nite fr 3 months....once stopped am back to sqare one.....third referred to a psychrist....he prescribed mirtaz 7.5 mg and zicam .5 mg in d nite now.... works well but with lot of side effects..... flatulence and headache and constipation......please help what to do