A person performed an Umrah Mufradah (independent Umrah) several years ago and later became certain that…

A person performed an Umrah Mufradah (independent Umrah) several years ago and later became certain that their ablution (wudu) at the time was invalid. The legal ruling requires them to perform another Umrah Mufradah to exit the state of ihram. This individual suffers from frequent doubts, particularly regarding purity and other matters. However, at the time of the Umrah Mufradah, they were relatively in control of their doubts. Now, more than two years have passed since that Umrah, and they are afraid to go and unable to follow the ruling to ignore their doubts because the doubts about the Umrah and its acts dominate them. Can they appoint someone as a proxy to perform the Umrah on their behalf to exit the state of ihram, given their fear and hesitation about going again? They are also doubtful about whether they entered the state of ihram and performed the rituals insincerely (pretending to perform them with their friends deliberately to avoid doing the Umrah) or whether they genuinely performed them with a proper intention but an invalid wudu. Someone advised them to appoint a proxy due to the hardship of their situation, but they are uncertain whether their condition qualifies as hardship since the legal ruling states that one with frequent doubts should ignore them. However, they are unable to let go of their doubts and hesitate greatly. Can they appoint a proxy to perform the Umrah Mufradah on their behalf, as well as another Umrah to expiate for the violations of ihram they committed during this period? It is worth noting that they live in the Eastern Province of Saudi Arabia and would need to travel to Mecca. Considering that some people experience fear regarding certain actions and are afraid to perform them, and that Islam is a religion of mercy, is appointing a proxy permissible in this case? Please provide a religious solution for this situation?