Technically, PMS and perimenopause are two different things. PMS is the time just before you get your menstrual cycle when your progesterone levels are fluctuating, That is when women feel moody, irritable, mildly depressed, weepy, bloated, headaches, etc. Then once their period begins they feel fine again. That is because progesterone levels and estrogen levels are beginning to stabilize once again.
Perimenopause is the time when a woman's hormones are beginning to shift and change on the way to actual menopause (12 consecutive months without a menstrual cycle).
Perimenopause symptoms are the same as PMS symptoms, for the most part, with a few others thrown in for fun :), but are much more erratic. Plus, with perimenopause, your cycles are unpredictable as well. Which is what you are experiencing right now.
Depression and mood swings are VERY common in perimenopause. Rages are also common for many, many women.
If your physician has said you are in perimenopause, then you need to either ask him or her or even an endocrinologist for some help in stabilizing your hormones.