Don't consider crying as a sign of weakness, you never should. Sadly... I can't shake that feeling, and for that reason I hate crying. I suppose it's because my father called me a baby when I was more or less in hysterics talking about how I was constantly thinking about suicide when I was 13... or even when he more or less said the same thing when I was having a panic/anxiety attack. Oh well. Anyway... is crying a sign of weakness? No, why should it be? It's a natural thing to do, and when you're sad, you have to let it out some way. You can't always control how your body reacts. If you're crying, and you just sit there and cry and NEVER do anything to try to fix something, I would consider that weakness. But if you cry, and continue trying to make the best of what you got, then how can you be weak? Doesn't that show that despite sadness you can overcome your troubles and fight through it?
So... I would never consider crying weakness by any point, and you should NEVER consider your ~emotions~ a weakness. They are part of who you are. Accept them, and work with what you have to get the best out of life. Sometimes things get hard, sometimes things don't work, but things can get better if you work at them.