That's how a lot of people are. The back is much easier to throw from a Muay Thai stance and usually more powerful since its your dominant leg. Making sure you step in with the back leg first(meaning your momentarily switching to a orthodox stance for you) helps make it easier and less akward to throw. The more exerience you get throwing the more comfortable it will feel. You most likely just haven't got the muscle memory for the lead leg yet.
Sometimes Jerry students and fledgling fighters struggle with what's called "lazy leg syndrome". That means that their kicks are slower and usually less effective than what they should be and its usually caused by one of two things.
First its important that you understand that your kicks will only go out as fast as you bring them back. Sometimes they relax too much and don't make the effort to bring them back as strongly and this can sometimes be evident by that leg and foot dropping as they retract it. Instead they need to adjust their balance and focus then on bringing that kick back as strongly as what they sent it out and pulling it back. This will make their kicks stronger and sharper.
Sometimes this is caused by a person having tight or weak muscles for retracting their kicks. Different muscles oppose each other to some extent and there are muscles you use for retracting your kicks that you don't use so much for sending them out. A student or fighter will be weak with those muscles because they are not used so much in everyday life or developed like those used that they oppose. This is why in my circuit weight training workouts I would not just do things like leg press and leg extension exercises but also leg curl exercises as well. Those muscles you develop in those first two exercises oppose that of the last exercise but in total will make your kicks faster and stronger.
If you run or jog you also might want to occasionally turn around and jog backwards short distances for developing those muscles that you use when running forward.
Look at your kicks and see if they are dropping when you retract them or are dragging them back and fix that if that is the problem. Also focus on bringing your kicks back with as much speed and power as you send them out. Also consider adding some exercises like lunges and curls to your workout with your training partner maybe holding your heels while you lay on your stomach and retract those lower legs with your knees bent while they give you resistance or adding some circuit type weight training to your workout routines.
Can't your teacher help you? Why are you paying him tuition if you can't ask him? We can't see what you are doing to make corrections, you teacher can. It can be many things from your timing, using your momentum wrong, the way you finish which will make it easy to grab, maybe you incorporate the hips wrong or not at all,.....
If your lossing balance and power its because your not shifting your weight
Ask your instructor for help with it that's what you pay him for
i take muay thai and im a southball (left handed) im great at kickimg with my back leg but i cant seem to kick with my lead i can even kick to the head with my lead without losing balancemim stepping correctly and my kicks come out "ok" but there slow and easy to catch anyone have any drills excercises or tips on maybe how i cam improve ,y lead leg kick? thx