What am I doing wrong?

I’m not a DIY kind of person usually but I wanted to try and paint my living room wall. I feel frustrated as this is how it looks after second coat 😖 Few months ago painted the main room and it was the same disgusting lines or shade/shine, I just don’t know whats causing this.

I used a brush, I don’t believe I can handle a roller (tried in the main room, it was a mess).

What am I doing wrong? How can I fix this? I don’t want to apply another coat as thats what I did in the main room and wall still looks the same, so Im doing something wrong when painting.

Any help is appreciated 😕