What motivates you the most - money or alignment with your natural interests? Look around the job market and pick a position to focus on that strikes a reasonable balance between the two.
Embedded systems engineers command great salaries, so do full stack engineers. I wouldn't recommend game development if you want to continue enjoying it as a hobby, the industry notoriously burns people out quickly.
Once you've decided on a position to focus on, search through a bunch of job postings and take notes on the skills and technologies that employers are looking for. Study those skills and technologies by reading books and working on toy problems that interest you. Putting together an open source project is a great way to demonstrate these skills to potential employers, but definitely not necessary. Be on the look-out for jobs and employers that seem particularly interesting to you.
When you feel reasonably in touch with the basics and fundamentals, start applying for positions. Start out with employers and positions that you don't particularly care for, use the interviews to practice your rhetoric and build your confidence.
Make sure to have trusted friends/coworkers/mentors in the field review your resume and give you feedback. I avoid listing any particular technologies on my resume, because sometimes they can box you in - but admittedly some employers will be looking for X Y & Z technology listed on your resume, so don't be afraid to make small tweaks for specific companies and positions you are really interested in. Don't be afraid to embellish your resume and work history - it's okay to say you led a team even if that responsibility was never formally acknowledged. Don't outright lie though, and be very prepared for interviewers to ask in depth questions about your prior experience - I usually bring a notepad with talking points to help me remember all the details of projects I've worked on. Don't be afraid to admit a lack of professional experience with some technology - having experience with such technology on personal projects can go a long way towards demonstrating aptitude.
Finally apply to those jobs and employers that stuck out to you - the ones you really wanted or were interested in learning more about. Try to give off a vibe of ambition and hunger to achieve, managers will pick up on those traits, whether consciously or subconsciously. Technologies come and go but soft skills are very important so feel free to mention that you're a great technical writer or that you are an excellent mediator of conflict, etc - it can help fill the gaps of experience or knowledge in a domain.
Most of all believe in yourself and your capacity to learn and grow - that will be the primary factor in your success.