from the past till now

[blouen]

Please help me with a word that means something has existed in the past until now.

[riverkid]

Please help me with a word that means something has existed in the past until now.

I'm not at all certain that there is one word in English that'll do all that, B. How about,

since ...

If your own language has one, I know how strong the urge is to seek the same in a new language and the seeming illogic that there might not be one is strong but hey, that's language.

[David L.]

Depending on the context, in English, you may be stuck with:
Formerly
Hitherto
Until now
Previously/previous to this
Thus far
To date
Up to now

[blouen]

I'm looking for an "adjective". Say a problem has existed since a very very long time and is still existent until now.

* This _________ problem ....

[David L.]

persistent
constant
uninterrupted
interminable
unrelenting
relentless
perpetual
unending
habitual
chronic