What birth control pill is better for me if i have high blood pressure and diabetes type 2 also one that will not make me gain weight?

Several options: Depending on other risk factors you could be a candidate for low dose (20 mcg estrogen) birth control pills. You could also use a Progesterone only birth control pill, or consider the use of an iud. Those options mostly don't cause weight gain - though some women are very sensitive to hormones and can gain weight easily with them.