That's awesome man! Teaching can be extremely rewarding and if that's your new found goal in life then go for it!
I don't know what your situation is but I just wanted to add if you wanted to get an engineering degree it really is never too late to go back. I was getting a degree in Comp. Sci when I first entered university but I ended up completely failing my first year because I spent way to much time on World of Warcraft. I decided to switch into another degree because I felt I wasn't "smart enough" which was an excuse. I switched into another easier degree program and managed to keep the few courses I did pass and put them towards the new unrelated degree. I continued gaming (moved onto LoL) and just coasted through the easier program and graduated. I liked the new program I was in, it was an interest of mine but I knew I wasn't going to be doing anything with it after I graduated. So I ended up graduating and getting that degree but deep down I knew I'd never forgive myself if I didn't just 'man-up' and go finish what I started the right way.
Fast forward to now and I am successfully going into my final year of my Bachelor's in Comp Sci. It's been one of the best decisions I've ever made and I can't believe I was going to give it up because I let gaming get the better of me. I still did struggle with games even when I decided to go back but the point is if you really want it you should definitely go for it.
Of course, I don't know your situation. I know that school is expensive and there might be some possible financial restrictions or academic restrictions or other things that might possibly prevent you from going back for your engineering degree. Those are definitely real factors. It's just that when you said you had 'blown your chances' at your engineering degree I totally thought and felt that way too of my situation. So I just wanted to add my story and let you know it's not necessarily too late to go back.
Having said all that, teaching IS an fantastic path to go down. Good luck!