Is it normal for guys to also feel insecure?

It can be normal, sometimes? But if it matters on your emotional, mental wellbeing OR body image. Don’t let it get to you if you aren’t perfect enough, it takes a while for you to be open to a friend or family member! You’ll get through it trust me!! And they share their opinions to YOU! Your not alone, I feel the same as well at times, but I only think about main goals (like school or just socialising!) and when It feels like it is the right moment to be insecure, reflect on what you’ve done good!

It sounds to be you're not aware of your strengths and mainly focused on negativity if you want to be stronger try and dwell on good things instead of worries that wont change anything just work on one at a time to build courage to solve the next problem. The reason we ask questions is to be aware of the possibilities and challenge our beliefs.

Yes. Men can feel insecure as well.

Yes, it's normal for everyone, even if they don't express it well

Yes, and it's also normal for them to hide it.