Can you get over depression yourself?

Feeling depressed , hopeless, a failure in life, missed my dreams , can't go back to 21 . Cry all the time & easily with sad thoughts of getting old, messed up life, worry of bills, stress of work & kids. Feeling like I will slave away & only drink & have nothing left. Why couldn't life had been better. I can't change the past but I am struggling to let go of the past of lost hopes & dreams & just LIVE in the present. I dunno why I can't . I think of my younger years & cry inside & it makes me feel hopeless. Just want to know if trying to cope with it is possible to do alone. Or do you HAVE to have help. I keep those feelings inside & just try to work hard & have been feeling a resentment to parents & childhood & life & how it has turned out. But I don't wanna go to a therapist as I don't wanna seem unstable or something. I tell myself you can get through but I just cry & get all stressed & depressed & get feelings of loss, hopelessness, feeling like i;m ugly or fat or a loser.