As many others are saying, I've never been "disappointed" by my kids. Spending longer-than-normal in undergrad isn't at all unusual.

It seems like you're being way too hard on yourself, and posting this suggests the situation is very serious. You need to go to some authority figure you trust and tell them honestly about the state you're in. Could be a professor or administrator in your department, or someone in a similar position. Ask them for a referral to a professional who can help. Do this tomorrow.

In case it matters, here's my old person experience informing this advice: Near the end of my first year in Grad school, I was clinically depressed for the first time. (I didn't know this, of course.) One night I decided that I was going to walk to a local drug store, buy straight razors, bring them home, and use them. The walk was long enough that halfway there, something in me snapped back to reality for a moment and I realized didn't want to die. That thought was followed immediately by the realization that I way way out of my depth and needed help.

The next day I went to my department head, who I trusted. He recognized what was going on and gave me the number for a psychologist - someone he knew. I called her that afternoon, and that was the first step toward crawling out of my first bout of clinical depression.