Your tree looks fine. Some leaf curl is normal. According to research by Purdue University leaving one fruit on a small citrus tree will not affect the tree's growth. This is because a citrus fruit does not draw energy from the whole tree, but draws all of it required energy for growth from only the three closest leaves to the fruit. Otherwise remove all additional fruit on such a small tree. A container grown citrus tree should produce 2 or 3 growth flushes per year, if fertilized and grown properly. You should not expect much growth after just 5 weeks. Your tree looks healthy.