The right time?

Do you notice that all important conversations happen in the middle of the night? Always before a significant meeting, or before or after a difficult day.

I'm only able to start any kind of tough conversation  if I'm tired as hell, totally unhappy and so overwhelmed that I'm indifferent about result. Because I'm to afraid to spoil good mood or romantic moment with a serious topic.

It is nearly impossible to stay calm and talk in reasonable arguments when you want to cry out loud. Instead of a useful conversation that helps you to connect with each other, you risk starting  a big fight. [great can mean 'very good']

Every single psychologist says that talking is a very important part of building strong relationships, but how to become brave enough?

[my advice (for what it's worth) would be to tell your partner all this and say you want to change things. If they are receptive, great. If they start another row, have a good think about whether this is the right relationship for you. Or get some help from a good psychologist/ counsellor/ relationsihp coach/couples therapist]

good luck