I know next to nothing about your field, but it seems to me that you have what’s needed: I’m having a hard time imagining anything missing, seeing as you already have designs CADed together that you can show off.
Is an internship an option, just so you get some practical experience? If I were to translate your situation into a field I k own better, you’d probably end up in the category of “probably qualified, but lacks experience”, which is the common catch22 job seekers have been faced with for the past couple of decades, so it might just be a matter of continuing to apply places that might give you this practical experience.