Know that the life of this world is but amusement and diversion and adornment and boasting to one another and competition in increase of wealth and children - like the example of a rain whose [resulting] plant growth pleases the tillers; then it dries and you see it turned yellow; then it becomes [scattered] debris. And in the Hereafter is severe punishment and forgiveness from Allah and approval. And what is the worldly life except the enjoyment of delusion.
Race toward forgiveness from your Lord and a Garden whose width is like the width of the heavens and earth, prepared for those who believed in Allah and His messengers. That is the bounty of Allah which He gives to whom He wills, and Allah is the possessor of great bounty.[Quran 57:20-21]
Regarding the fruits of our worship, we will inshallah find its fruits in life hereafter. If Allah wanted he could have given us fruits of our worship in this world, but it does not happen all the time. Allah wants to make sure that everyone who claims to be a believer is tested. Those who will have true faith will exercise patience and will keep their trust in Allah. Remember, we believe in unseen and often it is hard to believe in something we have not even seen. This becomes more difficult if we live at times when atheists are making fun of theists all over the world. Anyways, we who weak faith, will start doubting and may want to leave Islam so that they can enjoy the life they know exists for sure. This is one way Allah separates true believers from non believers.
Those who are true believers and exercise patience and keep their trust in Allah, soon starting seeing the fruits of their worship in this world in the form of peace, happiness, tranquility and contentment of heart. That's the reason you will see people who have strong connection with Allah Subahanahu Wa Taala are always content with whatever they have. They will be happy to share whatever they have. They might be poor but they don't hesitate to donate whatever they can to help poor and needy in the community.
On the other side, people you have no connection with God will always have anxiety, depression, greed, suicidal thoughts etc. no matter how many girls they have in their life or no matter how much wealth they have. Look at celebrities of our time, everyone of them is going through some sort of mental issues. No matter what they do, they can never find love and happiness in their hearts. Because love and happiness of our hearts and souls in only fond in remembrance of Allah Subhanahu Wa Taala. Allah says:
Verily, in the remembrance of Allah do hearts find rest. [Quran 13:28]
Stay patient and keep your trust in Allah. Allah says:
And no soul knows what has been hidden for them of comfort for eyes as reward for what they used to do. [Quran 32:17]
And your Lord is going to give you, and you will be satisfied.[Quran 93:5]
Except for those who believe and do righteous deeds, for they will have a reward uninterrupted. [Quran 95:6]
Theme of above verses is repeated multiple times in Quran.
So the key my friend is to believe in Hereafter as a reality which you can see. There should be no doubt in life after death and if you know that you will asked for anything we do with this life then you will fear Allah Subhanahu Wa Taala before committing any sin. If you know with 100% confidence that paradise exists and Allah is for real, you will do all acts of worship with love of Allah Subhanahu Wa Taala. When love of Allah Subahanhu Wa Taala find its place in a heart, nothing else can remain in that heart and that's when we start feeling happiness, love, mercy, tranquility even in this world.