From 40+ years down the road in front of you: Grades and internships will open the first doors for you - but that's all. After that, it is only your experience and competence that will open the doors. From the sounds of your message above I would say you have exactly the skills it will take to succeed: persistence, people skills, a joy in the work, and a willingness to learn and ask questions. As an experienced engineer who has headed up many projects, I would be glad to have you along my side and teach you the rules of the road. Hang in there. You have a bright future in front of you