Q.How Do I Get Rid Of White Fungi From My Soil?
My plants and flowers on this side of the garden are not doing well, they are struggling to grow. I noticed the soil has this white fungus which appears to be spreading.

Certified GKH Gardening Expert
That white fungus (really bacteria) is trying its best to kill off what is actually killing your plants. Likely a bacterial infection from soil remaining wet for too long without a period to dry out.
Unfortunately, I cannot see the plant damage from the photo. I will be unable to tell you, exactly, what is killing your plants. I can suggest way to get your soil back to a proper condition, though. If that fungus, or any other is growing happily, it means that the environment is better suited for microbial growth than it is plant growth.
First, check your pH, and raise it some. It is likely on the acidic side from the infection and its metabolites. DOLOMITIC LIME will take care of this.
Make sure that your soil dries out to AT LEAST 2 or 3 inches between watering.
Make sure to test your soil for pH swings and nutrient deficiencies.
Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/info/applying-bactericide-to-plants.htm
https://www.gardeningknowhow.com/composting/manures/fungus-growing-on-manure.htm