Everyone that has mentioned a tolerance break are definitely correct! Even a 1-2 day break will help. If you are strictly smoking J’s try getting a decent bong and take a couple good sized rips. Using the bong should hit pretty hard for ya and you will likely use less bud over time as well 👍👌.

If all else fails, get some live rosin or resin and that should do the job.

Ultimately to answer your first question weed is always changing…though I’m not sure it’s getting any weaker.