Is there anyway to explain hairloss...

[25 going on 65]

Many people just aren't capable of understanding without having lived it themselves. They literally don't have the mental tools, no matter how well you explain yourself.

If your mom has ever experienced significant disfigurement, from an accident or medical issue or whatever, you can compare your hair loss to that. If she hasn't, you basically just have to spell it out, possibly Scorpion-style.

Explain to her that you, like many other men AND women, have a condition where your body is irreversibly disfiguring itself (irreversible for now, anyway). Depression is a natural reaction to this, just as you would be depressed if you were disfigured in a fire or by flesh-eating bacteria.
If she tries to tell you not to be a "baby," or to "get over it," you tell her that she has never lived through anything like this, so she doesn't know what she's talking about. She may try to argue and bring up deaths of her family and friends, or other tragic things like that. At that point you simply tell her that none of those things are even similar. (It's not that MPB is worse than those things--it's that it's totally different, and therefore she cannot identify with anyone experiencing such a problem.)
You can also bring up the fact that she and your dad chose to roll the dice by having a kid, knowing that their genes had a strong possibility of forming a person who is significantly screwed up in some way (be it down syndrome or, in this case, androgenetic alopecia). In that sense you can tell her she owes you understanding, as well as material support in addressing your problems. (Would they neglect to treat you if you were born with, say, webbed toes?)

Of course, there's a good chance none of this will help her understand anything. That's our plight when talking to non-balding people.

However, I did seem to get through one friend's head by saying, "imagine you had a condition where one of your most readily-visible body parts was progressively becoming more deformed, with no current treatment able to reverse it. Imagine that the way others perceive you becomes totally different within a few years. Now, how long would you want to live that life? Would you really want to stick around to old age?" I think she got it.