I'm expecting you all to be brutal and honest - don't let me down!

I'm currently studying my MA and am now looking into doing a PhD. It's a fairly new idea for me, because I've taken everything pretty slowly so far (took a couple of years out before my MA). But I can't figure out if I should do it or not.

Firstly, I'm an introvert with shyness and self-esteem issues, although I have had my confidence boosted MASSIVELY over the past few years and am now fairly good at public speaking. Secondly, I've struggled with my mental health throughout my student life, including the couple of years of work in between. Thirdly, I don't have a solid idea for my proposal yet, and feel I'm approaching this all way too late!

I'm generally concerned that I won't be a good fit for the course, although I'd like very much to do it. I want to progress in my field, hone my craft, and eventually become a lecturer or work in academia. I want the support that the 3 years would give me. I would also rather do it now, considering I'm mid-way through my 20s and would like to settle down sooner than later. But I'm not an outgoing student, I'm not massively confident in my own abilities, and I'm worried I won't be able to cope with the extra pressure (although I don't want my mental health to rule my life).

I'm currently doing loads of research and brainstorming for proposal ideas, but there's still this doubt in the back of my mind. Is this uncertainty a red flag to begin with? Should I keep on anyway, apply, continue talking it over with my lecturers? Or should I accept that it might not be for me?

Any help or advice would be very much appreciated!

Don't worry, you won't get any brual responses on here unless you start making weird complaints about the hardship of having to carry a laptop to work each day :-D

Normally I would advise someone with mental health issues to get them sorted before undertaking a PhD because the PhD process can damage the strongest amongst us. I have still not recovered my sleep patterns properly 6 months after passing my viva and I got through the PhD without any major problems for example.
What is encouraging in your case is your statement about not wanting to let your mental issues rule your life. Make sure you remember that regularly as you go through the PhD process.

As for introversion and shyness? You will be in excellent company. Introverts apparently make up 50% of the population. We just don't shout about it. Academics are a weird collection of misfits. You will see many people who will make you feel like a party animal. I personally watched an academic panic and sharply dive into a shop when he spotted me on the high street to avoid just saying hello. Sadly for him but hilariously for me, it was an Ann Summers shop. I walked behind another person who did a u-turn when he saw me. He turned so quickly that he walked straight into the wall. Again, all to avoid saying hello. Hang on....maybe it's me that is the problem....anyway.......

In summary, I would say you are probably as good to go as you need to be but get those health issues seen to as much as you can before starting.

Good luck.