If an assumption proves to be false, is the research then meaningless? Last year, I did research (while in high school). My research was relatively successful and I was able to get a lot of amazing opportunities out of it. 

However, looking back at it now, I realize that it is possible that one of my research assumptions was incorrect (not definitely incorrect, but possibly). This was my first research project, so I was not really accustomed to making assumptions. Now, though, this is really causing me an extreme amount of anxiety and I am not fully sure why. I was proud of my research, but I feel like that one assumption makes the research worthless.

Is all of one's research meaningless if an assumption proves to be false?
The answer is not necessarily, for two reasons:


It may not actually matter. There are many assumptions that get made in research that are probably not true, in retrospect. Some of these are known to be false from the outset (in my field, it's the assumption that people mix randomly). Said assumption may not actually have all that big an impact on the final outcome, either numerically, or often as importantly, in the subjective takeaway from the project (Should I do X or Y? The difference between X is twice as good and X is 2.17 times as good doesn't really change that you should do X).
You learned something - presumably from actually doing the research, but also about the importance of critically evaluating your assumptions. This is a good thing, and at the high school level, probably the most important.