Every engineer already goes through a lot of struggle designing the initial prototype of the thing being designed, analyses the constraints involved, tries out different alternatives attempting to find the sweet spot that will satisfy them all etc. Then, exhausted and in love with the product of his effort, he shows it to people at some company or institution and they all have something to say or add to something the engineer perceives as already perfect or almost perfect, some might have valuable criticism, but some might just have no idea about the constraints involved because they didn't put in that much time into analysis, some just want to have their share in the potential success, some have to think about how to actually sell it etc. That surely is overwhelming, but it is part of the engineers work and I don't think "Work alone" is advice of much value. You simply have to accept this is just as an important part of your work as the design itself - I think most people never do. Then, you can starting learning how to best deal with it. Also, find a team or/and organization that you actually like, or at least can tolerate.