Sleeping pills won't kill you, most of them are safer than Panadol in an overdose.
On the NHS they have the drug Zopiclone (UK brand name Zimovane) for insomnia. It is a very good drug, it works well for the majority of people, and it has an excellent safety record.
Valium (diazepam), Xanax (alprazolam), Ambien/Stilnox (zolpidem), and Zimovane require a prescription. They are all class C drugs, so they do have a small potential for abuse however it is not common, especially if you do not have a history of drug/alcohol abuse. Ambien (might have a different UK brand name, perhaps Stilnox) and it (along with Xanax) are not available on the NHS but a private doctor can prescribe them. Zimovane and Ambien are "Z" drugs and they are very effective for sleep Xanax and Valium are benzodiazepines. Although most benzodiazepines can be sedating most are not appropriate to be used for sleep. Valium, for example, will alter you sleep architecture (brain waves when you sleep), as will most benzodiazepines. Temazepam is the biggest exception, it is a very effective hypnotic however it has a very unfavourable reputation in The UK. The only benzodiazepines available on NHS are Valium and the older, rarely used, Librium.
Avoid any over the counter medications, they are just antihistamines that happen to be sedating. But they are not particularly effective and are best for people who have a problem sleeping for a night or two on occasion. You really should be evaluated by a doctor and he can prescribe the best treatment for YOU. What works for other people may not the best.
Zimovane is probably your best option, especially on NHS. If a doctor offers you a drug like Valium ask about a "Z" drug instead because they have little impact on sleep architecture (most GP's don't know a lot about sleep architecture). I have taken it several times personally and it worked well, it should be available in 5 and 7.5 mg tablets. The 7.5 mg tablets are the typical dose for healthy adults.
Keep in mind a few things- hypnotics are safe and won't kill you unless you mix them with other drugs. The idea that sleeping pills kill is a remanent from when barbiturates were commonly used.
It is best to take hypnotics short term (5-14 days) but some people will benefit from long term use and "Z" drugs have shown to work well long term. However long term use is controversial, especially in The UK, probably the most hostile country towards sedative/hypnotics.
Addiction can occur from using certain drugs but the risk is extremely low.
And hypnotics are fine to use, they are not "bad" drugs. Insomnia can cause major problems for people and treatment is required in some cases. Sleep deprivation can cause almost any problem and costs billions in lost productivity every year in every country. Some might have a harsh attitude towards hypnotics but don't be taken in by those people.