You seem to be creating a lot of objects and then not re-using them, dismissing them, setting them to Nothing.
I can only think that's going to mean that as the code runs you will be leaving a whole lot of objects just kind of floating about unused.
That might not be the root of the problem though, have you checked if you get the error you describe when you search on a specific term/terms or try and access a particular URL/page?
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