Relax. I think you should choose a major that you know you can excel in, and that has all those courses you mentioned that interest you, from psychology to life sciences – a major such as neuroscience. Depending on the university you attend, there should be plenty of options for how to set up a major and minor (or interdisciplinary major or double major) to explore all the areas of interest to you. THEN you can decide what to do for graduate school and your career.
You could go to medical school with any bachelor’s degree. You could also get a master’s degree in engineering and become an engineer that way – you don’t have to have a bachelor’s degree in engineering. You can get a master’s in bioinformatics, genetics or genetic counseling, landscape architecture, documentary film-making, education (to become a teacher), medical illustration or whatever else interests you at that point. You could also pursue a PhD and go after a research career, or become a counselor or psychologist. You could go to a graduate program to become a physical therapist or many other options.
Most graduate degree programs do not require a specific major to enter them – they do require a high GPA usually and high standardized test scores, a showing of interest, and a few courses as a foundation, some of which you can typically take as a graduate student.
In addition to graduate degree programs, there are numerous “certifications” out there that you can study for on your own and take exams to become certified or qualified for a particular job. For example, with a science bachelor’s degree, you can take the patent agent exam and become a patent officer and work on patents, either for the government, a corporation or a law firm assisting attorneys.
Even without certifications or a graduate degree, you will have options. You could write about science for science magazines and news websites, for example. You could sell scientific products. You could learn to program (with free courses line) and develop science apps. You will only be limited by your imagination.
Yes, the job market seems depressing and competition seems fierce – for almost all majors. And if you read up on doctors, you’ll find that many are leaving that profession as well or certain areas of practice because of health insurance developments and liability. You can worry about those things later. Right now, focus on sharpening your strengths and pursuing your interests, and think creatively about the possibilities of where they can lead.