Dependence on substances or addictive behaviours can have a serious impact on sleep. Your GP is a good first contact. The following organisations also offer direct support:
Gambling
GamCare run the National Gambling Helpline: 0808 802 0133 - free, 24/7. They also offer online support and face-to-face counselling: gamcare.org.uk
Drugs
Talk to FRANK can help you find local support services: talktofrank.com/get-help/find-support-near-you
Alcohol
Alcohol Change UK offers guidance and support: alcoholchange.org.uk
Other Addictive Behaviours
SMART Recovery supports people dealing with any addictive behaviour through national meetings and online programmes: smartrecovery.org.uk