So as the dream goes,

I had gotten home from somewhere with not only my mother, brother and sister, but also my aunt and two cousins. We had all this stuff from wherever we had been and we just put it wherever and the house was soo messy and also hot, I kind of couldn't stand it. So I had to put this thing in my room, it was like a giant bug net but in the shape of a one man tent thing. I left my room to see what was going on in the house but when I came back there was a spider on the floor in the net roughly the size of a foot, but it was just standing there so I just assumed with all the other stuff we brought home, we got some fake plastic spiders and my bro and cous were playing a joke on me.

So I left my room again and came back and there were more fake bugs, all the size of feet atleast but I hadn't seen bugs like these but I didn't realise that in the dream. So I thought, well I guess we need a place to keep our fake bugs when I looked up and saw one of the giant bugs crawling on the roof of the net. I went to get my cousin and brother to show them because it was pretty cool. Before we went in to my room I was like "ok guys, this is soo cool!" then my cousin said "It stinks here." I shrugged it off and opened my door to see that not only was one giant bug crawling on the roof of the net, but there wee two more crawling on the walls of the net and when I checked the spiders on the floor of the net, they were moving and then we saw one bug that was still. I stood up to reveal one huge arm and ran at the wall of the net and started punching really had to escape. I thought oh crap, I'm gonna have to sleep with these. And we got kinda scared as we realised that about 12 or so foot-sized bugs that looked very dangerous were about to escape into the house and be able to hide anywhere in the mess around the house.

Since you first thought the spiders and insects were fake and then they turn out to be real, the dream could be you unconscious telling you that you haven't been taking a situation seriously enough.