None of what I'm about to say is advice, just my experience. I'm an oldish person who's been dealing with this for decades. I lost a parent when I was a preteen and sort of slammed the brakes on my feelings as a way to cope.

I apologize in advance for the indelicate comparison I'm about to make, but I recently had my first experiences with psilocybin, and found that (at least for me) it acted as a sort of "emotional laxative". It didn't cause me to immediately break down and sob or anything, but over the following weeks I had brief moments where I actually felt some of these clogged-up emotions and was able to open up the release valve a bit.

Afterward, listening to certain emotionally-charged songs or certain types of cinematic scenes was occasionally enough to tip me over into a short crying jag. This would last a minute or two, then I'd suddenly be back to "normal", but with a strong sense of relief from getting some of that out of my system.