Carseat frustration

Dee

I'm so frustrated with car seats. I have an 1997 extended cab f150, and our uncle was kind enough to get us the chicco fit2 carseat. Only the base is 21.5 inches long, my seat is 15.5 inches. I feel like I won't be able to find one that fits my back seat and I'm trying really hard not to panic and get depressed. Anyone else struggling with car seats?