Know this, you ARE significant. The Bible says in Psalm 139 that you are fearfully and wonderfully made. There's nobody else like you. God made you with detailed and loving intracacy. And if you were the only one that Jesus needed to die for, He would have done that just for you - that's how much He loves you. Your worth is not determined by what you accomplish, but in who God has already made you to be when He created you. Let's not fall for the trap of comparing ouselves to someone else, or trying to achieve something to determine your worth, because you are already loved by God and the Bible says that even the hairs of your head are numbered.
The Bible also says "From one man he made all the nations, that they should inhabit the whole earth, and he marked out their appointed times in history and the bounderies of their lands." (Acts 17:26 NIV). I believe one key way we can look at this scrupture is that God has set us in this specific time in history, and our bounderies are marked out for us. Even where we live is significant in God's amazing plan - you are where you are for a reason.
I believe God expects us to do our part, and theres grace from God to do what He has specifically called us to do. We don't need to be popular or accomplish something so that everyone thinks we are important, we just need to do what God has called us to do with all our heart. A Scripture to consider is the parable of the talents in Matthew 25:14-30. Notice that according to this scripture, people were held accountable based on what they did with the number of talents they received, not based on what they did not receive. So lets do our best with what we've been given. Let's work with all our heart as unto the Lord. There's grace from God to do what we are called to do, not for what we are not called to do.
Our significance is in Christ, and our lives are hidden in Him. This takes the pressure off to try and be something we are not. Let's ask of God for grace to do His will, let Him open the doors of opportunity in our life (see Revelation 3:7-8), and just follow His leading. In doing so, you can have the opportunity to influence people for Christ that quite possibly nobody else would be able to reach, while producing the fruit that God has uniquely called you to produce in your life.
Allow God's joy to fill and refresh you, because He truly delights in you. You are extremely significant and your contribution to this world is so important. God loves you and He will be with you every step of the way!