Hi Olga, is it the areas near the tips that you are mostly concerned with then?

One thing I noticed initially is that your shape is not aligned with the world axes, it is kind of sloping a bit:



This will kind of tend to make it harder to make symmetrical and do further steps on, I would recommend making these things aligned to the world axis and it is also helpful to locate it near the origin so you can snap on to the world x and y axis as references while drawing to keep things aligned.

One thing you may try for the tips is to add in an additional profile section near the tip areas.


Another idea is to not try to model the tip so directly immediately with the sweep, instead let the sweep extend forward just a bit and end in a planar cap, like this (this example one I chopped off the end of your sweep with a line using boolean difference):



And then fillet that:




- Michael