Hello,
If both you and your wife agree on all terms of the divorce such as maintenance amount ( can be none of both parties agree) etc, you can apply for divorce with mutual consent. This usually takes 1 year as it involves a mandatory waiting period. Case can be filed jointly if it's mutual divorce.
Relative Impotency is not an absolute ground for granting divorce. If the court feels that your medical condition is treatable, they might not grant you the divorce.
Hope this helps.