Well without pictures to say for sure it sounds like it is over-watered or is lacking a certain nutrients. Look up a guide for whatever kind of tree it happens to be to make sure you feed it like it should be.
this is how you can solve your problems with your plant. all you need to do is check the soil and make sure that it is moist and not dry. you need to keep your soil moist for it to grow good and you should also check to see if its getting to much sun
