Answer: Based on your description, I think the tree may be suffering from overwatering since you are watering and it has been raining both. Your goal is only to keep the soil evenly moist but not sopping wet. So, if it has been raining or if the weather is cool, you may not need to water so often. Use your finger to reach down into the soil and see if and when you need to water. When you do water, make sure it penetrates deep into the soil. A less frequent deep watering is better than a daily or every other day sprinkling.
Another possibility, if you do not think you have overwatered, is that the recent cold snap caused some frost damage to the foliage.
Finally, if you do not think it is either one of those causes, you might want to take a sample and consult with your county extension as to what is wrong with your tree and what steps to take next. Alternatively, you could check back with the nursery where you purchased the tree, especially if it is under a guarantee.
It is not usually a good idea to fertilize a new tree or a tree that is under stress, so I would not recommend doing that. Trees may benefit from an application of compost and/or a general purpose, complete, granular fertilizer (such as 10-10-10), in an amount indicated by the label instructions. For deciduous trees, sprinkle it on the soil surface in very late fall (after the leaves have come down) or very early spring. You could start doing that this fall.
Good luck with your tree.
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