Sudden jolting and power loss?

Hi there, I have the vehicle listed above 323f, 3 speed. Last Sunday I took it out for a drive. A little extra detail if its an identifier to the issue, starting the car i usually have to press the throttle to get a little bit of fuel into the carb otherwise she doesn't start then first turnover she starts then turns off then second turnover she starts and runs. Now I took her on a drive for around an hour and a half when suddenly she jolts a little and starts feeling less responsive but it's nothing too worrying as she's a little unresponsive and you can feel when the cars gears change and then as I continue to drive it gets worse and worse. As soon as you touched the throttle it would jump a little on the rev counter and jolt, lose power and try to stall. I was lucky to even get her home and turned off. She also still jolted while in park when revved. I haven't looked under the bonnet yet but was wondering if anyone had a clue? We were thinking it might be a carb strip needed.