The confusion over the use of the terms hypothesis and theory can be difficult to sort out. We have popular usage, popular impression of how scientists use the terms, and how the terms actually get used in science. All three perspectives share some things in common, but none of them match completely. Popularly, hypothesis and theory are used almost interchangeable to refer to some idea which is vague or fuzzy and which seems to have a low probability of being true. In many popular and idealistic descriptions of science, however, the two words are used to refer to the same idea, but in different stages of development. Thus, an idea is just a hypothesis when it is new and relatively untested - in other words, when the probability of error and correction is still relatively high. However, once it has successfully survived repeated testing, has become more complex, is found to explain a great deal, and has made many interesting predictions, it achieves the status of theory. This is not an unreasonable perspective to take - after all, it makes sense to try to use terminology to differentiate younger from more established ideas in science.
In reality, however, such differentiation is notoriously difficult to make. Exactly how much testing is really required to move from hypothesis to theory? How much complexity is needed to stop being a hypothesis and start being a theory? Scientists themselves aren't rigorous in their use of the terms. For example, you can readily find references to the Steady State Theory of the universe - it's called a theory (even though it has evidence against it and many consider it disproven) because it has logical structure, is logically consistent, is testable, etc. Perhaps the only consistent differentiation between hypothesis and theory which scientists actually use is that an idea is a hypothesis when it is being actively tested and investigated, but a theory in other contexts. It is probably because of this that the confusion described above has developed. After all, while in the process of testing an idea (and now calling it a hypothesis), that idea is treated very specifically as a tentative explanation. It can, then, be easy to conclude that hypothesis always refers to a tentative explanation, whatever the context.
If you try to use hypothesis to refer to more tentative ideas and theory to refer to more established ideas, you aren't doing anything wrong - especially if you make that clear at the beginning. A problem only develops if you insist that others do so as well and that this is how real scientists use the terms. As far as facts are concerned, scientists will caution you that even though they will appear to be using the term in the same way as everyone else, there are background assumptions which are crucial. When most people refer to a fact, the are talking about something which is definitely, absolutely and unquestionably true. For scientists, a fact is something which is assumed to be true, at least for the purposes of whatever they are doing at the moment, but which might be refuted at some point.
It is this implicit fallibilism which helps differentiate science from other human endeavors. It is certainly the case that scientists will act as if something is definitely true and not give much thought to the possibility that it is wrong - but that doesn't mean that they ignore it completely. This quote from Stephen Jay Gould illustrates the issue nicely:
Moreover, 'fact' doesn't mean 'absolute certainty'; there ain't no such animal in an exciting and complex world. The final proofs of logic and mathematics flow deductively from stated premises and achieve certainty only because they are NOT about the empirical world. ...In science 'fact' can only mean 'confirmed to such a degree that it would be perverse to withhold provisional consent.' I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms. The key phrase is provisional consent - it is accepted as true provisionally, which means only for the time being. It is accepted as true at this time and for this context because we have every reason to do so and no reason not to do so. If, however, good reasons to reconsider this position arise, then we should begin to withdraw our consent.
Note also that Gould introduces another important point: for many scientists, once a theory has been confirmed and reconfirmed over and over again, we get to the point that it will be treated as a fact for pretty much all contexts and purposes. Scientists may refer to Einstein's Special Theory of Relativity, but in most contexts Einstein's ideas here are treated as fact - treated as if they are simply true and accurate descriptions about the world.