Have you ever just stopped and thought about how faithful God really is. He loves us, protects us, provides for us, and He even puts up with us! It is truly amazing that we can be partakers of God's grace and mercy and it ought to cause us to be thankful no matter what. In 1 Thessalonians 5:18 Paul says that we are to give thanks in everything because this is the will of God for us in Christ Jesus.
In my opinion, there is a big difference between being thankful "in everything" and being thankful "for everything." My wife broke her leg a couple of years ago and it was a very long healing process and required surgery. I did not walk around thanking God that this happened, but I was able to thank Him in the midst of it.
I don't know what you are facing or getting ready to face but just remember that the Lord is faithful 100% of the time. He knows what is going on in your life and nothing can happen to you without Him allowing it to take place. You may never know the reason why, but you don't have to. God does not owe us an explanation. The question to ask is not "why is this happening?" The real question is "Lord, what are you trying to teach me?" I believe that is a question that God will always answer if we are focused on Him through faithful obedience. Take some time to reflect on the faithfulness of God and listen to what He is trying to teach you!