Absolutely not. Being in a relationship brings just as many (if not more) problems as single life. It's true about needing to be happy with yourself in order to have a successful love life.
For the guys thinking "if I met a woman who feels the same way about life as I do, we could make it through together", sorry, but that's bollocks. To the vast majority of women, overly emotional men (suicidality being the peak of that) are the biggest attraction killers out there. I felt exactly that way, met a woman who matched that description, and thought I'd found what I'd been looking for. She was attracted to me because I understood and could empathise with her. Mostly she liked that I felt how she did but managed to stay positive and overcome the negativity.
After being together for a while she came to see much of my positivity was simply putting on a brave face. In reality, she liked me because I put all my effort into lifting her mood. I noticed that on my down days she would treat me with contempt, as if it became clear that I didn't have all the answers and was a fraud. We would sit and talk about her and her problems for hours, but the moment I expressed my true emotions about life, the conversation would be brought to an end.
This was a woman who I had known years before and thought was fantastic. Same sense of humour, good conversation, fun. My ideal companion. As soon as the relationship started, most of that disappeared, and my job was to keep her happy, and if I didn't, there was hell to pay.
Another woman I've been with loved my fun, cheerful attitude. She got me to open up about my reasons for being suicidal because she thought she could fix it. When it became clear that saying "think about your family", and "suicide is a permanent solution to a temporary problem" didn't work how she thought it would, she got angry. You could see the attraction die. She liked to say "I'm always here for you to talk to", when in fact she only was if she had nothing better to do. Once she pretty much forced me to open up about my issues when I didn't want to. One of her friends then called her and she immediately dropped our conversation and left to go shopping.
Sorry for the essay. I'm just trying to convey the fact that depression and heavy personal issues are not attractive, and relationships with that undercurrent are doomed for failure. I've known people who cheat on their partners despite knowing they are suicidal. It's a brutal world.