okay my car feels different then usual when i press the gas. It seems that it used to immediatly acclerate when i press the gas and lately it's not gaining speed or accelerating as it should be. i put my foot on the gas and it kinda lingers around 25mph then really really slowly will get a little speed. Now it really sucks when i'm merging on the freeway anyway does any one know what could be causing this?

it's an automatic which means it should automatically shift gears?but it doesnt feel like its doing that either