I feel like you’re being hard on yourself.
The medicine probably has changed things a little bit,
But lack of sleep is a big deal, its definitely hurting you.
All that in addition to feeling insecure about your ability to work/skill is holding you back.
The meds are a small part of that,
You need sleep.
Try an over the counter sleep aid or benedryl,
And never sleep during the day!
You’ll feel better and your welding will improve, building your confidence.
I really, really think the sleep is your biggest issue.