Four years ago, I had an accident and had to stay in bed for three months. Unable to sit, I would offer Salah while lying on my back and without Wudu' (ablution) for two months.
Is this permissible?
If the situation is as you have mentioned, there is no blame on you and your Salah is accepted. Allah stated,
So keep your duty to Allâh and fear Him as much as you can
However, if you were able to perform Tayammum (dry ablution) and did not, then you must repeat Salah.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.