Temperature valve for water heater

Hello my name is Becky. I am trying to raise some money to get a temperature valve that is needed for my water heater. I've been without heat, hot water for about 2 months now and it's been difficult , it's starting to get chilly now so I need to get this soon. I already fixed the other problem that the water heater had but the last thing that it needs is this temperature valve. I am on a fixed income and don't have any extra money for it The cheapest one that I found for my prefab mobile home is around $534 so if you could donate anything it would be so appreciated. Thank you so much and God bless.