Do you feel overwhelmed by training, or by a situation that you do not control?: You cannot have control of all situations, wanting to control everything is a need to feel little confidence in yourself or in others. If you know that you can do a task or activity well, focus on one small thing, develop, complete it to the best of your ability, and then focus on something else. (Attention to details make the difference)

Do you feel that you are skinny even though everyone tells you that you have a lot of muscle?: Ok, when we see an object or person, more than just noticing the main characteristics, we can also perceive an emotional feeling or reaction. The latter, in fact, is the one that most marks our way of seeing the world. If you look at yourself in the mirror 24/7, you live comparing yourself consciously or unconsciously with others, you will have distorted expectations because your emotional approach to "how you see yourself" is based on how others see themselves. The best thing you can do is compare yourself to yourself, as long as you have the same goals.

I got injured and/or stopped training a guy and now I don't have the same performance?: In the previous point, comparing yourself with yourself is positive as long as you take your situation into account and know very well what your level is. Remember that it is your process and your life. The training routine should be adapted to your level, not you to it.
The idea is that you feel comfortable with your results and your progress, and that regardless of the circumstances, what you do, you do it for yourself. Value and take care of your body.