First of all, I'm surprised your pdoc didn't increase your Lamictal dosage. Therapeutic dosage for Lamictal ranges from 200mg to 400mg, and it depends on the person. Either way, 150mg is not therapeutic, and your pdoc should have tried increasing your Lamictal dosage first. Obviously 200mg is not therapeutic for you.

Second of all, why would your pdoc prescribe you Lexapro daily and Fluanxol PRN? Lexapro on its own caused an upswing for me, and well... since you're not on a therapeutic dose of Lamictal and you're only taking Fluanxol PRN, you'll probably become hypo/manic. Is your pdoc trying to test if you're bipolar or something?