I met my GF online a few months ago. I'd only hooked up with girls before and had never seriously dated. From the beginning, I didn't have this strong excitement to see her (I haven't had this feeling since HS) but I thought dating her might change things. Looking back that seems analogous to "let's have a baby to save our marriage" and it seems like a mistake.

While I've been conflicted about my GF, she has been just the opposite. She constantly says how she feels like we're getting so much closer and then she started dropping the "L" bomb. At the same time, she has no problem countering this "caring side" with violent mood swings and severe depressive days (like she turns all my comments against me and drags us both down). The latter is the reason I just never grew to feel the connection with her (in addition to just having different senses of humor and interests).

A few months ago I tried to break up with her just saying that I didn't see a long term future. She cried and begged me for another chance saying that things would change. I relented as I thought maybe I could actually grow to love her.

When I felt even less close to her (and an incident happened in which she just yelled at me for 2 hours to say I wasn't trying hard enough to pursue her) I went to break up with her again. This time, she countered with saying that she couldn't be left alone (she cited severe depression and suicidal thoughts) and asked me to at least sleep on her couch so that she wouldn't do anything. After sobbing all night in her bed and just saying "please" for 10 solid hours, I told her I just wanted to see other people. She said "you can go on other dates, I just don't want you to leave forever". Seeing little downside, I once again hoped it would work.

The last month I've really tried. We both read the "5 love languages" book and tried to better appeal to satisfy each other. This has brought us to our current state. She's head over heels in love (and saying that she's never felt closer) and I feel like this is the biggest sham of my life. I've never lied to her about my feelings (namely saying I love you) but I've acted interested in her day when I really wasn't and bought her gifts just so she wouldn't keep saying "WHY DON'T YOU EVER BUY ME FLOWERS??".

I know that she's not the person I want to marry, and her texts often feel like an annoyance when I see them. I'm honestly not sure if I can take breaking up with her in person again and I kind of want to just write her an email in hopes that she can be comforted by her family. I'm afraid she's going to be hit by quite a shock.

So is breaking up via email an exceptionally bad thing to do? If so, is there a right course of action here?

tl;dr: No connection with GF, she used threats during the last breakup attempt, not sure if I can just write an email.