Air carrier Flight Attendant reported a fumes event during initial takeoff. After troubleshooting and conferring with the Captain the flight returned to the departure airport.

Narrative

Immediately upon takeoff from ZZZ; a strong odor permeated the cabin. At first it smelled like exhaust fumes; then escalated to the smell of burning fuel; then burning plastic. FA2 (Flight Attendant 2) and myself; FA4; were seated in the back and got up to feel the lavatory doors for heat in case there was a fire. None was felt; so we looked inside and found neither smoke nor flames. In fact; the trash compartments in both lavs had popped open on takeoff so it was easy to see there was no issue inside the lavatories. The smoke detector in the forward lavatory then went off. I saw the FA1 and FA3 check that lavatory and decided to grab the PPE and halon extinguisher and head up front just in case they needed it immediately. There was no smoke or flames present in the forward lavatory either; however the odor was still strong throughout the cabin. The Captain called about the lavatory smoke detector and after a quick discussion; told us that we would be returning to ZZZ and back to the Gate. He made an announcement to the passengers; we prepared the cabin for landing; and we landed about 10 minutes later. The entire flight lasted about 20 minutes. The odor did not dissipate until after we landed. The entire crew reported headaches and feeling dizzy. Three of us removed ourselves from the flight.