Sleeping problems and irritability

I'm looking for a homeopathic therapy for a series of problems that I have, specially insomnia and irritability. I'm a 36 years old female, mother of a 9 months old baby, having normal family life and sedentary but satisfying job. My problems with insomnia start in 2003, with apparently no reason. At the beginning it was occasionally (2-3 times/month) and I wasn't able to fall asleep and/or I was sleepless after 2-4-a.m. During the breastfeeding period (I was waking up every 3-4 hours/night) it aggravated, I wasn't able neither to fall asleep, nor to sleep after 2-4 a.m almost every night. Now I don't breastfeed anymore, but I still have problems with insomnia almost every night: can't sleep after 2-4 a.m. I have palpitations, headache, thoughts about things to do or small everyday problems. Sometimes I fall asleep around 5-6 a.m., sometimes not. In the morning I feel very tired and irritable. I tried to use valeriana (before pregnancy) and antistaminics lately, but without satisfying results.

Here is some other information that could help you out: I'm very tall, slim, vegetarian since I was 13. In 1996. I was diagnosticated with hiatus hernia and since then I have to eat small frequent meals. Before pregnancy I was suffering from constipation, now I'm regular. I don't smoke, don't drink coffee (stopped during pregnancy, before 2-3 cups/day), dont' drink alcohol (stopped during pregnancy, before 2-3 glasses/week). My cycles is six days long, very regular, very painful before pregnancy, now painless but abundant.
I'm going to the gym twice a week.
I am a hard worker, aggressive and strong-willed, concerned with small details. I have a strong temper and can be unapologetic. I tend to expect the same high standards from others, both at work and at home.
When it comes about my dreams, they are very realistic. Cold weather makes me feel worse.

Thank you in advance.