Is resistance training (i.e. weights) out for now because of the blood pressure issue? If not, it could be a helpful component.
Josh and Steve are right: it would help if you (and we) had a more specific picture of what you eat now.
Keep this in mind though: Metabolism is a very tricky, scientific thing, blah blah blah, when it comes down to the details. However, eating and exercising to get it headed in the right direction doesn't have to be! I doubt you or I have any intention of passing a written exam on the nitty-gritty of metabolism. But we both would like to get a grip on it in day-to-day life.
In other words, get a plan down,
give it time and don't worry too much (which is a common problem).
