Answer
You need to find out about any local drug user clinics in your area. Usually they will be operating a needle exchange as well so you can get free syringes. They will also give you details of NHS clinics which offer free bloodwork and liver function tests. They will treat you with complete respect and offer only help and advice knowing they cannot dissuade you from what decisions you have made. CLASH in London, is my local and its fantastic. You can call the National Drugs helpline to give you information about clinics in your area.