There are a few extra things to consider when you have both asthma and hypertension.
First, you should probably avoid beta blockers and ACE inhibitors (like Lisinopril). Because of the way beta blockers work, they often block the beta receptors on respiratory passages leading them to constrict. ACE inhibitors also have an "asthma equivalent" side effect that is remarkably common.
Calcium channel blockers are usually considered the best for asthma patients, like Norvasc. Since you are still having problems even on Norvasc, then you may want to consider some alternative approaches.
First, though, do you have sleep apnea or nighttime asthma? If you do, a CPAP machine could solve your hypertension problem altogether!
If you have already tried lifestyle modifications (i.e. you eat right, are not overweight, etc.) then you may want to try vitamin supplements or therapies. Some that are definitely worth looking into include garlic, CoQ10, hawthorn, pomegranate, potassium, calcium, magnesium, the Resperate device (breathing and music therapy) and Zona Plus (discovered by the Air Force).