When you're facing a challenge, no matter what is, regardless of difficulty, you know what propels you? Lets take running for an example (its the only thing i can talk about from experience). Being completely honest, If i didn't have motivation, I would just quit at about 800m, when I'm pretty tired.
Training propels you for 10% of your challenge, Motivation propels you the remaining 100% (no, thats not a typo)
I started jogging in September, i started from scratch, had nothing at all. And when i say nothing at all, i mean 100m slow jogging was enough to kill me. People in my school thought they were so awesome for being so fit, etc... And they thought just because your overweight, you can't run or do any strenuous activities. I never forgot the day when one of them said 'you can't do shit, so go sit on the side' Back then, my initial target was 800m, even though i only made it to about 700m, then i was completely dead. The frustration of not getting anywhere, after 4 months of work, was unbearably annoying. This however, out of all the issues of my life, i decided to fight back. I struggled, late nights out on the street, pushing my body further than it can handle (and further than i can handle). God will always reward you for your effort, always. Whether its months later (which it was), or years later, he will reward you.
2 weeks ago i just set a benchmark, 2.5 Kilometers. I thought it was a fluke, but i did it 3 times in a row. I'd made it, and proved everyone wrong. How did i do it? I just decided, that I was gonna run, till I collapse. The night before that, I was dead by the 1.2 Kilometer mark. How did it double? I gave it 110% of my effort, and i was rewarded
Moral of the story, whether its family issues, running, studying. In order to make progress, you have to give 110% of your effort, and trust me when i say this out of experience, the feeling of achieving 110% percent has to be the best feeling ever. What motivates you? The will to be a better person, the will to prove EVERYONE wrong, The will to be in better places. To get there, you must work hard for it.
When things for everyone around you are going amazing, and they've got everything you don't. NEVER give up, keep fighting, even if you give you gave your all, I guarantee you, absolutely guarantee you, it'll pay off soon.
Motivation is everything