Heartiest congratulations! You are truly on the right path. You know why you got peace, less anxiety and you stopped watching all that stuff? It is because meditation takes you nearer to your soul i.e God. Soul is God. So when you come close to God or to your true self, you get peace and you gets detached to the worldly things and desires.
God/Soul is desireless. So when you come in contact with your soul, you also starts to become desireless. Secondly WATCHING PORN, MASTURBATION, Relationship other than your wife is considered BAD KARMAS and NOT AT ALL accepted by HIM. So by meditation, you got yourself saved by doing such SINS.
This is TRUE and ONLY path of humanity and is the ONLY ONE that is ACCEPTED by the creator.
Second thing that I want you to congratulate is your dedication and consistency. The CREATOR loves dedication and regularity. Even though you meditated for only 15 minutes, the fact that you didn't even miss a single day is really LOVED by the creator.
Everyone loves Money, car, family, relationships and what not. Have you seen anyone who LOVES GOD? Those who truly LOVE GOD gets emerged into GOD/soul and gets free from the painful cycle of births and deaths.
I truly felt delighted when I read your post. You are on the right track. However, I would like to give you a sincere advice. I am telling from my personal experience.
ADVICE: Instead of meditating on sounds, START MEDITATING ON GOD'S NAME. It can be anyone who you worship or believe in, such as Ram, Krishna, Jesus, Allah. This is the true way of meditating and the same have been preached by ancient saints and yogis.
Trust me, you will get many times more peace and calm when you do mediation on God's name. Importantly, Whosoever name you chant, you will start LOVING HIM. And that's where the magic starts. The moment you are in LOVE with GOD, your mind will be detached with the worldly desires and materialism. More you chant the name, more calm you feel in your mind and more you get yourself detached.
I think it became a longer post. Anyway, I just shared my personal experience.
Keep it up buddy and follow this advice. And don't thank me later, only THANK TO THE CREATOR.