I think I have replied this post in other sexual health forum.
I think you should contact a doctor and a find a solution as you cannot continue taking tablet and long use of any tab will make it in effective eventually. As a sensible approach, you may stop taking tablet and stop sexual activity completly for 3 months. You may recover without any treatment or you can do some exercises which can incresse blood circulation of the groin area. this itself can cure your problem. Research for other exercises for sexual functionj.
This is simply performance anxiety. Take a break and relax. Do not use Levitra anymore. Everything will come right again, do not worry.