I would add to this that holding yourself to what you think are the expectations of others isn't fair to yourself. It seems like you think you have to hide how

I would add to this that holding yourself to what you think are the expectations of others isn't fair to yourself. It seems like you think you have to hide how badly you feel you are doing, and that shame is keeping you from asking help. Stop that. You have nothing to be ashamed about. You have tried really hard despite many times being knocked down. Making mistakes is normal, and not doing well when not being guided is also normal. These are not things that reflect badly on you as an engineer, let alone as a person. So stop beating yourself up. Then ask for help. If no help is forthcoming either escalate to your manager's boss, or quit and find a less shitty place.