If you don't like your housemates much or course mates, you need to go out and find people you do like and can hang out with/ live with. That's pretty much the whole point.
If you are capable the course will take care of itself. There will always be boring/hard/shit bits on any course, you just have to get through them as it sounds like in general it's more good than bad? First years on broad maths based courses generally a bit dull as its later on the fun specialisations come in.
Get out, find people, have fun. It's not that it's the best 3 years evarz, but just a great opportunity to to go out try things and meet tons of people that you probably won't get again in the same way.