I think 90 minutes every other day is good, but it's obviously causing you pain, which is less good! Maybe try 45 minutes 5 days a week? Or even 30 minutes every day.
Pain is bad. Your body is trying to tell you something. Causing yourself pain will most likely equate quitting exercise altogether ...well, it does for me! If I hurt, I stop doing what makes me hurt! Luckily, there are many choices when it comes to exercise. Explore them!