I'm not sure that you have to hit rock bottom before you can start rebuilding your life smirfy, and whats rock bottom for some people may be different from another. I can tell you of my experience but it may well be different from other people here, perhaps they can tell you after I recount my experience.
My big breakdown came as a huge shock, although looking back now I'm surprised it hadn't happened sooner, I had been under huge stress for over 2 years at work, the whole workplace had and I since have realised that at least 4 of my close colleagues had been treated for depression (one so bad he had to be kept in hospital), my line manager committed suicide a month or two she and I had an argument, none of us were offered counselling, not even the young typist that found her and her dog in the car 2 days after she had done it. I partly blamed myself for her death, which was probably unjustified. I'd been feeling very tired and sort of isolated for a few weeks then one day when I'd had a normal and fairly good day and suddenly it was like a fuse had blown, I'd just got back from a local cross country event and suddenly I was in tears, wouldnt (or couldn't?) get out of the vehicle, wouldnt let my husband near me, he phoned a close friend who got me indoors somehow and I went to bed, the following morning I was having panic attacks at the thought of getting up and couldn't bear the curtains open. My OH had to get the doc out as I couldn't get out of bed and I was diagnosed and started getting treatment. I think it was about 2 months before I went outside and then not on my own, I had about 6 months off work and it was a slow process feeling anything like normal, I hated being on the medication and I now realised I took myself off it much much too soon.
I'm convinced if I hadn't ignored or misinterpreted the symptoms leading up to my breakdown it could have been prevented, I didnt realise I was depressed and I'm sure if I had gone and got treatment earlier the breakdown wouldn't have happened. I've heard so many times from different sources that "only the strong get depression" because apparently strong people battle on and on where weaker people give up, perhaps there's something in that, I don't know. But you may have noticed I, along with several others, encourage everyone that comes on here to see their GP to get their treatment started as soon as they possibly can.
Since then I have been able to recognise the symptoms creeping up - mostly lethargy, short temper, unexplained tiredness, anxiety, disrupted sleeping and eating patterns and apathy - and go to my GP as soon as I realise what is happening (my symptoms are usually triggered by a period of prolonged stress). This time I realised I needed to go to the doc and made an appointment for the following week but for some reason everything suddenly got worse much more quickly than usual and I had a sort of mini-breakdown which thankfully has been fairly short lived and I am now 'only' very badly clinically depressed.
I hope all that has helped, if you want to know anything else please dont hesitate to ask and I will answer best I can, sharing experiences hopefully can help us all, I've certainly learned a few helpful things in the short time I've been a member here.