I have released all my negative thoughts and replace them with positive ones.

Release is a gentler operation than eviction. Thoughts do not leave because they have been told to. Mostly they leave because you stopped holding them.

There is a difference between a thought passing through and a thought being gripped. You can carry a worry the way you carry a phone, for hours, with no awareness of the muscle involved, until you set it down and feel your hand unclench.

Replacing comes second and cannot be forced. But you can notice the grip, and noticing loosens it slightly, and slightly is the unit this kind of change actually comes in.