i am by no means an expert on delonix regia but i would strongly advise not giving it any more fertilizers and additives until it reaches a more healthy state.its a young plant and can recover if you let it. your dealing with a plant that doesnt care for wet or even humid conditions so remember, as you gain more experience with bosai in general you will learn to not expect instant results. your mindset will become long term and patience will become second nature. one more thing, it may be weird to some, but i talk to my plantsevery time i a[[roach them. while there is zero evidence to back this up, it helps. ive brought back literal sticks to life, maybe it has nothing to do with reality, but you will never convince me of that. if i had to guess anyone who has a love for bonsai has learned, or brought in with them a deeper spiritual connection with the art and the trees. you are not the master, the tree is. you only help it to achieve its potential.