Nervous to lift heavy weights (like barbells)

When I started out oh I struggled lifting that heavy bar but I kept at it and sure enough within about 2-3 weeks I was able to add weight. Same with squats, it was a huge struggle and the bar resting on my shoulders hurt but I stuck with it and have since added weight to the bar. The squat and bench machines in my gym have a spot/side rail kind of thing on the side, so even if my arms give out and I can't push it back up, I can drop it on the side rails and it will stop the bar from falling on me. A lot of people at my gym don't use this safety feature but I sure do! Same with squats I use the side rail safety feature. Once you build up your stability muscles you will be able to balance better and not be shakey or wobbly. My left arm was very weak when compared to my right arm but now they have the same strength.

Squats were very tricky for me in the beginning because I felt very wobbly and not as stable as others. I also felt like I couldn't go as low as people in videos but it finally dawned on me that depth comes with time and sure enough I can dip down to where my thighs are parallel with the floor or slightly lower. Be patient but stay persistent