Firstly have you taken the shahada? Not just saying the words but knowing what they mean. The two pillars of shahada are rejecting taghut when you say "la ilaha (no deity)" and believing in Allah when you say "ila Allah (except the one Allah)".
"There shall be no compulsion in [acceptance of] the religion. The right course has become clear from the wrong. So whoever disbelieves in Taghut and believes in Allah has grasped the most trustworthy handhold with no break in it. And Allah is Hearing and Knowing." [2:256]
As you see, rejecting taghut will give your the most trustworthy handhold which can never break. This is what you need. I suspect that is what you're missing since you seem to accomplish the obligatory prayers, and I assume fast and zakat if you can.
You may ask yourself what is a Taghut, know that the taghut come in many forms,
Ibnul Qayyim (May Allaah have mercy upon him) said:
“At-taaghoot is anyone whom the servants go beyond the due bounds, whether it is someone worshipped, obeyed or followed.”
The taaghoot are many, and their heads are five:
1. Iblees (Satan), may Allaah’s curse be upon him.
2. Whoever is worshiped and is pleased with that. (ex. tyrants, celebrities, presidents)
3. Whoever calls the people to worship them. (ex. pharaoh, cesar)
4. Whoever claims to possess anything from the knowledge of the affairs of the hidden and unseen. (ex. "sufi saints", "rafida imams")
5. Whoever judges by other than what Allaah sent down. (ex. democracy, communism, capitalism, nazism, liberalism, feminism, other man-made ideologies)
Make sure you reject all taghut before you enter Islam completely. And Allah (swt) knows best.
