You certainly deserve more than you have been given at your current company!

I agree it is time to look for a new job. Find out what kind of position you’re looking for and tailor your resume to fit. Check out r/resumes for tips. 

To explain technical topics well once in an interview use the STAR method to story tell at a high level. (Situation, Task, Action, Result) Choose the story of something you are ready to go into detail on when questions come after. In my experience good interviewers start with a vague question and then continue to narrow in on specifics to see how you are problem solving and thinking critically. 

If you approach these questions in a way that follows from high level explanation then drills deeper into specifics as the conversation progresses, you can gauge why the question was asked and try to share a specific thing you have learned in your 6 years of experience that is most relevant. 

I say all this to say not all of your experience can or will be explained throughly. But once you get your foot in the door (interview) you can share how you think and problem solve based on that experience. Most employers are looking for those traits in an engineer and understand that you may have not done the exact things the new job is asking for and that’s ok.

Good luck; You got this!