Well that's very interesting... Spirits seem to be attracted to you and your girlfriend.
But why "bad" spirits? It could be something you're doing to attract them towards your house.
Even if it's not on purpose, that's a bit scary to deal with.
I think the reason you're crying is because you were kind of scared about the whole ordeal and it's surreal to you, I don't doubt you one bit...I've had spirit encounters before and I started to tear up too, because it's kind of exciting, but it could also be you're feeling empathetic...feeling the spirits emotions around you or they're actually inflicting emotions (whether it be theirs or just something they made on you). Hope everything turns out well...that sounds very scary to deal with. Have you considered moving? I mean if it gets out of hand you should consider it, or get a priest to bless your house.