If suffering of others is my own suffering, then is my own suffering suffering of others?

While reading https://www.reddit.com/r/Buddhism/comments/6jl8gu/guru_rinpoche_on_the_mahayana/ I stumbled upon an excerpt:

Train in feeling that the suffering of others is your own suffering.

I'm a person who tends to go really hard on myself and so a lot of overworking for the sake of others, lack of self-compassion, a lot of comparing myself to other people and my "achievements" to their "achievements" - in a way, I think I've pushed this quote above way too far, to the point of it hurting my life on a regular basis. But then, as my mind is rather mathematical, I saw a one-sided relation there and I immediately asked myself, does it also work the other way?

In other words, is my own suffering also suffering of others? Should I treat it this way? Does causing me to suffer also cause others to suffer?

This change of point of view completely changes my perspective and the way I'm thinking about myself and, frankly, it's quite revolutionary for me to think of myself in such a way. If the converse is also true, then it completely changes the way I actually should treat myself, which is, to be honest, not like a trash dumpster anymore.