Limited Motivation

It sounds like you are an incredibly capable and talented person!  You just haven't yet connected to your deepest passions or desires.  Everyone needs a motivator to pursue something, and it sounds like when you have that motivations... maybe at times just to prove you can you do really well.  It sounds like a missing piece for you is to create the next goal... the next step that also inspires and motivates you to keep going.  Since you already acknowledge that you have committed yourself to being a mother and feel good about that and haven't given up, you clearly are capable of sticking to something that you deem important. 

You have some choices as to working on your follow through and commitments to your goals.  You can work with a qualified, experienced life coach, seek out really good therapy to work through the blocks to your success... either of these options would be good choices for you to gain clarity, understanding and direction for you.  Often times people don't 'finish' what they start because they don't really know what they want, or where they want to go.  Do you have goals, aspirations and dreams?  Maybe it's time you sat down and really thought about that... Maybe you need to look at what you really want in your life... have you always settled for good enough, rather than the best you can do?  Are you willing to make a commitment to YOU, YOURSELF, or have you minimized yourself and what you want, and say that it doesn't really matter...?  These are tough questions, but if you are willing to commit to yourself as you have to your child(ren) and future husband, then you will move forward and value your needs, goals and desires as much as you seem to value others...

I hope that this answer gets you started, and moving forward with drive, determination and purpose and then I know you won't quit...