It's much easier to use `grep` for your case. E.g. this way:
grep -o ''
In case there are `<` between `..` you might want to try this instead:
grep -o ''
However pay attention that it might return a data you don't expect for strings where you have multiple `` occurrences in the same string.
`sed` doesn't work for you because `/pattern1/,/pattern2/p` instructs `sed` to print all lines between line with `pattern1` to line with `pattern2` (including lines with patterns).
The problem might be solved with `sed` as well, but it depends on `somestupidstuff` content (e.g. whether it's the same in all cases or not, etc)