To be grateful/thankful is a decision that a person has to make for themself. No one can make you be happy or appreciative which are by products of gratitude. It's totally up to you. It's a matter of perception. Are you a person who sees the glass half empty or half full? Are you always focused on what you have or what you do not have? Are you a person who sees the good in everything or do you constantly complain and find fault?
It's amazing but being grateful is actually good for your health. Reseach has shown that being grateful/thankful can improve our emotional and physical well being. Gratitude is defined as the quality of being thankful; readiness to show appreciation for and to return kindness.
I encourage you to embrace the attitude of gratitude. Everything may not be just the way you want, but know that your days are blessed, you are blessed and you are blessed to be a blessing. Give thanks to God for the things that He has done. Thank Him for what could have happened, but did not. Look at what you have, speak positively and do not cancel your harvest with complaining. Let gratitude have a work in your life.