5 years is a long span of time. But still i recommend the above suggestions of reconciliation by my learned friends as the same would also be the top most priority of the court once case is put forth before it.
Having said that still if you want to pursue the litigation option then on the face of the given facts there appears to be the following remedies that can be claimed:
1. Cruelty: Any of the spouses withdrawing themselves from the society of other, not fulfilling any of the marital obligations, acting in total ignorance and having disregard towards the basic necessities and wants of the other spouse and even cold behavior towards the other spouse are good grounds for claiming this ground.
2. impotency: The ground is marriage could not be consummated. A person due to some psychological or medical reason is not able to do so. it is not necessary that there should always be physical impotency which can always be denied through production of the medical evidence. A person may be medically fit but can suffer from psychological impotency i.e. not able to consummate because of some psychological issue with other spouse,
Keep in mind before opting for litigation that the burden to prove the above grounds would be on you so you must have clear and cogent evidences to support your claim.