Why does Dora need therapy? Because she is unhappy with herself, and doesn't know how to stop being unhappy with herself.
A therapist isn't magic - s/he cannot "fix" people. But what they can do is guide you along. You go in, tell them what's wrong, and what your plans are for fixing it, and the point out unhealthy or untrue thought patterns that are tripping you up. It gives you a place to say things that you don't want to tell other people, and you don't have to worry about damaging that relationship. This person is paid to listen to you blather about yourself and your problems.
I've been in and out of therapy for the past 10 or so years. Sometimes, it's quite helpful. Other times, not so much. It largely depended on the therapist, and how willing I was to accept their interpretations of me and my solutions. Some of them were idiots. But others have really helped me and pointed out where I am ignoring a real problem, or how I'm hurting myself. Dora could benefit from constructive criticism (couldn't we all?) about her behavior from someone she doesn't have to trust, like, or get along with. Coming from someone like Faye, Hannelore, or Marten (clearly not a good option anymore), it could come off as incredibly hurtful and judgmental. Raven, Penelope, Cosette, or other cast members don't know her well enough to do it in a way I think she'd believe. No one can win. She doesn't need therapy because of one failed relationship. She needs therapy because people have deeply hurt her, and she can't stop hurting people she cares about as a defense mechanism.
Therapy isn't for hopelessly-broken people only. It's a tool one uses when they feel there is a problem. It can be as simple as needing a sounding board, or as much as needing someone to hold your hand and walk you through your solutions. Maybe you need to be referred to get medication, maybe not. None of these tools have to be permanent fixtures in your life. You do what makes you feel better and get you to be better-functioning. When you feel it has run its course, you stop. If it doesn't work, you try something else. Therapy isn't an insult.
As for
in vino veritas, I can't say I'm more truthful when I've been drinking. I'm about the same, but I tend to say more than I should, and make more solid declarations on feelings I really don't have that strongly. Sometimes these things are true, but they're often not. I could say them in better ways that are more accurate, or I'm reacting too strongly to a stimulus that normally wouldn't make me act that way.
Girls cry when they have to dump someone, it's not fun. Girls especially cry when someone bear hugs them and tell them they have to get help because something's not right with them. Faye, who didn't want to be with Marten, is telling Dora she's crazy for not wanting to be with Marten. What?
Has Dora ever dated an ambitious person or have they all been hipster townies? Maybe Dora should try dating someone different before she's deemed crazy and needs help? Maybe a guy that is nice to you isn't always enough in a relationship?
That's kinda sexist to make such a blanket statement about why girls cry. Some girls don't cry when they dump people or when they get bear-hugged/told they need help. Why do Dora's tears need to be linked to her sex?
Dora also said repeatedly how happy she was with Marten. She didn't break up with him because she didn't like him. She left the relationship because she couldn't stop thinking he didn't love her, no matter how much he told her that he did. I don't recall Dora once criticizing Marten's ambition or lack thereof (and I am not trolling archives to prove it for myself, but I am happy to be disproven here), so I don't see why an ambitious person would change anything, if Dora had the same reaction she did to Marten.