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This is caused by a lack of pollination. You can try attracting more pollinators to your garden or you can hand pollinate the plants. Here are some articles that will help with both:

https://www.gardeningknowhow.com/edible/vegetables/squash/pollinate-squash-by-hand.htm
https://www.gardeningknowhow.com/garden-how-to/beneficial/creating-a-pollinator-garden.htm

Here is a link that will help.

https://www.gardeningknowhow.com/garden-how-to/watering/watering-garden.htm

This is typical behavior for a squash plant. They will produce mostly male (non-fruiting) blossoms early in the season and will gradually start to produce more female blossoms as the season progresses. The male blossoms typically drop from the plant and seemingly disappear. Give it some time and you will see it start fruiting. Here is more information: https://www.gardeningknowhow.com/edible/vegetables/squash/squash-blossoms-falling-off-vine.htm

If you are seeing fruit but they are falling off, this article will help: https://www.gardeningknowhow.com/edible/vegetables/squash/squash-fruit-falling-off-the-plant.htm

While it's okay to prune some, you should only try to remove the growing tips so as not to leave large wounds that may draw squash pests and diseases. This article may help as well: https://www.gardeningknowhow.com/edible/vegetables/squash/should-you-remove-squash-leaves.htm

If the main stem died back, it has a 50/50 chance of growing a new stem. But really, at this point you are as good as starting from seed. I would recommend replanting seeds and starting over rather than waiting to see of this one recovers.

Yes, fertilizing every couple weeks is a bit much. Generally this is not necessary, especially if you amended the soil at the time of planting. You may be getting an abundance of growth from an overload of nitrogen, which may actually limit your squash production. In the meantime, if you need help supporting your large plants, I would simply place a trellis at the base of the plants and gently take some of the vines and place them along the trellis to direct their growth onto the support. When they set fruit, just tie the fruit in a cloth hammock (I like to use panty hose) to the trellis to provide extra support.