Lamotrogine rash?
 

Any one suffered from a Lamotrogine rash?
If so what did your doctor do?

I missed some does and then started taking it again and now I have a rash. My psych told me to lower the dose a bit and see if it goes.

Has your doctor had a look at your rash? There are some that can progress very fast to making all your skin fall off & killing you (Stephens Johnson Syndrome), but others where you just get a bit itchy.
If your doctor has had a look at it, best follow their instructions rather than random Internet people. If it gets worse, go back to your Dr, and if it's getting worse fast, A&E.

Might be worth maybe with a marker pen drawing round where it ends right now, so that if it gets worse you know for sure rather than from a guess of where the rash reached before?

It is all over my stomach a d back so if it spreads to my arms and legs I should notice.

Doc told me to go to a&e over the weekend if it gets any worse.

Thing that worries me most it that if it doesn't get better with the lower dose then I have to come off the Lamotrogine even thought it has been great for my mood and I had no side effects :(

Although it would be a pain to come off lamotrigine it is really really important to stop it if the rash is very bad. Like Duck said it can occasionally be a stevens-johnson's rash which can be life threatening so you definitely need to follow your doctor's advice!