Can someone tell me the meaning of ガンアゲ? It's giving me a hard time
The sentence is 気分になると一気にガンアゲになっし
ガンアゲ is a no-adjective that roughly means "(extremely) hyped up". It is considered as a ギャル語/JK語 word.
Etymologically, there is a phrase テンションが上がる, which is a little slangy phrase meaning "to be excited" or "to be hyped up". The antonym is テンションが下がる ("to be turned off"). Someone started to contract it and say テンアゲ/テンサゲ. Then someone even shortened it and coined アゲ/サゲ. ガンアゲ is a stronger version of アゲ. This ガン is a slangy intensifier similar to 超. It's also found in ガン見 and ガン無視.