I second journaling.

I don't know if you read the Harry Potter series, but in it, there was a magical device called a pensieve. A wizard could extract their thoughts and memories with their wand and place them into the pensieve to help them gain mental clarity, keep certain memories they might find vital stored away securely so they don't lose them, or a way to transfer bad memories and thoughts out of their head so that they could better their own psyche.

I find that keeping a journal is the muggle/no-mag (non magical persons) equivilant of this, and it's done wonders for me. Some find it only serves to keep them in a deep state of rumination, so be wary of that.