I think the two most crucial points are the following:

1. You can’t force happiness and an optimistic attitude. In fact, if you push to hard, this might result in the other person not feeling understood and therefore make the situation much worse.
2. Negative emotions don’t get any better if you push them away or try to overpower them with optimism. Instead, you’ll have to face them.

Thanks for putting together this piece, the above mentioned points line up with what I have experienced personally. It’s funny that the actual resistance we have towards our negative emotions is responsible for the pain. Coming to terms, talking about and accepting our negatives is the way to actually get through them.

You can’t push away the pain, you can only feel it, accept it, talk about it and work through it. That’s the only way to get over it.