Assalamu'alaikum.
If we were given tests from Allah, make ourselves clear by presuming the benefits/consequences of the tests, instead of saying "I know there're reasons for this." but we actually keep regretting or even keep blaming on ourselves, endlessly.
For example, one day you got a news saying that your friend was getting married with a rich dude. And you, who still single got jealous :\ And.. started to question yourself, "Why my time has not come yet? I wish I look prettier than she is..Aaaaah. I know there's a reason why I'm still single. But what?? Why Allah gives me this kind of test?? Stressful. Bla bla bla...." Ahha. Delete all those dialogues, and start thinking positively. Replace those words with "I know I'm not ready for this. If I so stubborn to get married with any of the men, perhaps my life would be a disaster. Allah knows I'm an immature lady and He doesn't want to burden me with all the marriage problems because He knows who I am. I know Allah saves a noble man for me to guide me and the family...."
But, what happen if one day you will get married to a man of your choice and your life is not happy as you expected? Please, return to the basic of life, Islam. Remember, Allah never puts any burden on a soul that is beyond its ability to bear. This means you know you can face the problems but you have to do the actions. Seek the solutions by referring to the expert ones. Don't keep crying or whining endlessly (it's okay to cry sometimes) and blame yourself and say "There will be no solution to this problems." Keep on trying and do not give up. Stop making any efforts only when you are dead (when the soul and the body are separated).
Ehem. What about other problems? It's okay. Grab the problems and befriend with them, and have a talk.
You : Why you are here Mr. Problems?
Mr. Problems : I didn't intend to come to you. If possible, I don't want to see you sad by having me in your life. But, who am I to do so? Allah sent me to you just because He loves you, seriously. He wants to see, what would you do when I'm around? Will your Iman strengthen? Or you go astray from Him?
You : But why me? I hate this. I hate you.
Mr. Problems : I know. Nobody wants me. Nobody wants to be in difficulty. But, do you know? There are ease in every difficulty, and there's a partner to every created things. So, when you have found my partner, which is the solution (the opposite of me), I will be with her, and both of us will not disturb you anymore. But perhaps a little memory will stick.
So, have a STRONG faith in Allah. Try to strengthen the faith everyday, insyaAllah.
Wassalam.