It is rather spooky this happened at the time of Halloween, you just could not make that stuff up!
Your poem is very well crafted, making it very personal about your trauma, but also in a way that can be taken metaphorically. This poem can be taken in the view of anything being a predator, and how it attacked its prey.
The tone is dark which again matches the season and holiday. I love the idea of Gossamer, especially being as your title because it draws you right in to the poem.
But you actually describe yourself as this, and then further describe that to make you even more vulnerable and trapped... very well worded!
Hope you are doing much better now... maybe the spider just wanted to be part of your next poem????