General Prefixes:
* Anti- (opposed to): Anti-sentiment (opposition to a particular feeling or opinion)
* Pro- (in favor of): Pro-sentiment (support for a particular feeling or opinion)
* Pre- (before): Pre-sentiment (a feeling or opinion that exists before something happens)
* Post- (after): Post-sentiment (a feeling or opinion that exists after something happens)
* Re- (again): Re-sentiment (a feeling or opinion that is felt again)
More Specific Prefixes:
* Nostalgia- (longing for the past): Nostalgic sentiment (a feeling of longing for the past)
* National- (related to a nation): National sentiment (a feeling or opinion shared by people of a nation)
* Public- (relating to the public): Public sentiment (the general feeling or opinion of the public)
* Popular- (liked by many): Popular sentiment (a feeling or opinion that is widely shared)
The specific prefix you choose will depend on the meaning you want to convey.