Does stress cause health issues as i have had anxiety for a few years off and on and i've recently had it come back and i'm very stressed and starting to get issues like itchy skin,headaches,i've been hot and sweaty more often for no reason aswell?

It's possible, but please don't try to diagnose yourself. Appropriator you to see your General Practitioner for a full physical examination and lab tests. If you don't have one, nows the time to find one. GP may also want you to see specialists such as Dermatologist, Psychiatrist, Allergist, etc. There is help available for dealing with your anxiety.

Chronic stress, tension & anxiety do eventually cause physical ailments. Your physician can refer you to a mental health professional who can administer stress management therapy which should be a big help for you.

It is not feasible to provide an opinion without additional history, physical examination may be some tests. It would be prudent to see your doctor to see if you may be depressed. Depression is treatable. Counter-intuitive as it may seem, exercise may help. Start with low intensity exercise such as walking and gradually increase the intensity as tolerated. Drink more water. Wish you good health!