join a sports club, that gives you common ground with other people. arrange to do something with your housemates. you have to be slightly aggressive and actively get yourself into conversations, and make things happen, for example in your society just go up to a group and get into the conversation etc. it can be hard at first but you have to push yourself and make it happen. you're at university to learn and get some new experiences, this is part of that learning curve and will help you later.