slight cold, extreme thirst + trouble sleeping

I have been out of sorts of a few weeks now, I first noticed that I had a vaguely blocked nose and my right hand sinus appears to be blocked most of the time too. I have been having difficulty sleeping for long amounts of time, generally only getting about 5 or 6 hours, but when I am in full health i sleep for more like 8 hours. I have a bit of a cough + cough up some thick yellow phlem sometimes. I also feel extremely thirsty even though I am drinking the same amount of water as normal. I tried upping my water intake and it made no difference (except to make me pee more). My period is also a couple of days late + I have noticed a slight weight increase, but I did a pregnancy test and it came back negative.
I was wondering if any of this could be stress related, or if i have some kind of virus. I am planning on going to see my doctor as soon as the easter break is over (as i am on holiday at the moment). But any advice would be really helpful