It should be a double breaker.
It should take up 2 slots.
Some take up two slots but only have a single rest lever.
Others take up 2 slots with 2 levers but there is a metal rod between the levers so they are ganged together.
How to Install a 240 Volt Circuit Breaker
If you have an electric stove the dryer breaker should look like the stove breaker just a lower amperage rating.
Something very weird here.
If there was only half the line (120 volts) (which the breaker seems to point to) then there should not be any heat unless the heating coil is grounded.
But you said you do get some heat.
The heating coil runs off of 240 volts and the Neutral is not part of that circuit. Same goes for the timer motor.
FYI: The power to a dryer is two 120 volt supplies that are 180 degrees out of phase. So one side L1 to Neutral is 120 volts and the other side L2 to Neutral is 120 volts but 180 degrees out of phase. So when L1 is positive 120 volts, L2 is negative 120 volts and therefore the voltage from L1 to L2 is 240 volts.
Might be time to call an electrician.