Cant take Viagra cause I take nitrites,I have diabetes,and I have had quadruple byp?

is there anything I can take to improve the blood flow in my . I use to be pretty large a little above normal size when I was younger. now that I am 45 with health problems.quadruple byp, diabetes, high blood pressure, plus I have had lower back surgery (fusion) I cant use Viagra, cause I take nitrites for angina or horny goat weed because of my high blood pressure.it feels like it wants to slide into my pelvic area and it hurts.its always cold because of the lack of blood flow.I have started working out to better my over all health.at least 3 times a week for 30 mins a day.I take at least 12 different pills per day.for my heart,blood,and sugar.