I would imagine if you could easily get away from these things that are bothering you, you would have already done it. Therefore, I would be cautious about wearing ear plugs or doing anything that will completely block out the stimuli all the time or very often because it is possible that you will become more sensitive, and if you are ever forced to deal with it again, it may be much seem much worse to you as a result. If possible, you could try to desensitize yourself to some degree. If a certain noise bothers you, try to expose yourself to the sound in a controlled environment. This way, you can slowly build up a tolerance to it. You can also figure out what kind of thoughts and/or actions help you deal with the things that bother you in this way. For example, you could experiment with some not so obvious stimming or practice counting to ten or meditating, as was mentioned in another post, while exposing yourself to a sound or other such thing you find problematic.
I am extremely sensitive to florescent lights, perfume, and loud noise myself. When I first started attending college I was extremely stressed and exhausted all the time. (The first time the fire alarm went off, I thought I was going to meltdown and crash right then and there in the library. As things turned out, I just wandered around in confusion and almost lost track of all of my books and supplies. -__-) Exposing myself to similar things I was exposed to on campus and the regular exposure I got from attending classes helped me quite a bit with the noise and smell sensitivities; however, exposure did not help with the lights.
I am also subtly trying this with an aspie student I tutor, and it seems to help somewhat with him as well.
If it is possible for you to get away for a while, you could try to regularly take a walk outside. For myself, I find if I can take a break (a short break) from the things I am sensitive to, they do not bother me as much when I am exposed to them again.
I hope you find something that works for you. ^__-
Edit: Is it possible to talk to your roommates about the things that bother you? I know not everyone is understanding, but some people are very willing to adjust their behaviors, at least for short periods of time, in order to help others cope with things. Perhaps if they understand certain things stress you, they could do things differently or let you have breaks from time to time.
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While Mr. Kim... has fallen prey to the inexplicable need for human contact, let me step in and assure you that my research will go on uninterrupted, and that social relationships will continue to baffle and repulse me.
- Dr. Sheldon Cooper (TBBT)