I bought a house one year ago. I did not know but this house has an underground drain in the garden which is in the back of our house.  This drain helps to lead  an underground  water flow, not to go into the house. Since I came in this house, I got bad health issues for me and my kids and I got a lot of legal court issues and money troubles. These troubles are painful, I wish I could move to another house ! maybe not everything is related to the drain but I would like to try something. 

I know there is an ancient feng shui formula that consists to flip the front of house to the back of house. I would like some advice on the matter. 

Thanks !

These are some considerations:-

https://www.geomancy.net/content/feng-shui-resources/feng-shui-articles/you-and-your-home/underground

https://www.geomancy.net/content/feng-shui-resources/feng-shui-advice/other-topics/baubiology

As no two locations are the same, a proper triage is recommended.