Marathon - My new passion

Hi guys,
This is my new passion. I realized kinda late in my life after smoking, unhealthy diet, physical activities and others.
Now I have to register for my lifes first Half-marathon.
I couldn't do it this year. I have a big exam next month. I may have to start my journey again. I did one half-marathon my self on Feb in the name of my republic day. I was not exhausted totally. I felt like I may can do couple more miles. I was confident but something have stopped me. I did it late but completed it.