Did I screw myself out of graduate school? I graduated from a state school in 2009 with a 2.77 overall GPA. I technically should have graduated in 2008, but was only going part time, so I stretched it out and became a "super senior." I'll be the first to admit...I struggled with undiagnosed mental health and alcohol abuse issues for the majority of my early-mid 20s, so I simply didn't apply myself as much as I could have. 

After I graduated, I had a really tough time finding a job in my field, so I decided to start taking some courses at a community college to see if perhaps I should try for a post-baccalaureate degree in another field. Many of which I did well in, with the exception of one F. THEN I made the asinine decision to go full time at a school about 1.5 hours away that I had to drive to. That lasted all of 2 months and by the time the semester had ended, I bailed...I didn't even take the time to withdraw. I simply allowed myself to fail out.

A decade later, I'm a marketing professional with 10 very successful years under my belt. I've worked some odd jobs to make ends meet, but I ended up excelling at a small nonprofit...then I moved into working as a contractor at a well-known retail store corporate office, now I work at and volunteer for the local branch at a nationally recognized nonprofit. 

I'm married, own my home, have an amazing child, and I go to therapy regularly and take medication daily. I finally have my life together, but I've grown bored in my field and need something more in my professional life. I decided to look into graduate school awhile back and really took an interest in instructional design. I feel like my background, which includes a lot of graphic design, could prove to be quite useful in the field...and I have a genuine interest in helping people learn. I could go into more detail as to why I feel I'd be a good fit in the profession, but I'll save you all the elevator pitch. haha

The trouble I'm afraid of running into is my past...While I didn't give my all academically in my 20s, I KNOW I would as a person who is now in her mid-30s. I want better for myself and of course I want to show my daughter that you can do whatever you set your mind to. A lot of the programs I am looking at will accept a 2.8, others (like my Alma mater's) program will accept a 2.4 if you've been out of college more than 5 years, with 2 letters of recommendation. I have co-workers/supervisors/etc. that would be happy to write these letters for me... However, I'm scared the grades I received while screwing around at different schools while trying to figure out my life AFTER I got my bachelor's degree are really going to negatively impact my chances to move forward.

I guess I'm just wondering if anyone has any insight on whether or not grad school could be in my future with the history I have or it's simply a pipe dream at this point. Any thoughts would be greatly appreciated!!
If you intend to pursue a professional career and not a career in research sector, I would say "apply with no hesitation". Do not let your doubts and cognitive biases prevent you from accomplishing all you deserve.

For someone in your age, grades do not matter anymore. Even for someone straight out of college, I would say that grades do not really matter. It's more about your experience, characteristics, and capabilities. Based on your post, I think you could easily prove those criteria to your future employers.

Regarding a career in research sector, grades might matter. Grades represents your academic discipline and how you methodologically attack problem statements. So, you need to do very well in the course of your graduate studies.