mMy lLife

In titles, we capitalize the start of words, but it can be more complicated than that.

I don’t know what this feel now but Iing is, but I promise to never give up I promise.

Simple grammar, no huge problems. Reply if you need further explanation.

mMy lLife

You need to use capitals in titles.

I don't know what this feel nowing is, but I'll never give up. I promise.

I don't know what thisI'm feeling now but I promise to never give up I promise.

I'm not 100% sure of what you meant so you could also write (I don't know how to feel right now)