To be worried about teen and MH?

[Cantthinkofadecentusername]

Bit of background.
I had MH issues that started around 12/3 with what presented at the time as 'normal' teen angst, it spiralled and got out of control, my behavior at times was frankly appalling. I saw phycologists, psychiatrist, CPN, ss were involved, problems continued right until now (early 40's) however I have learned to manage them. I've bounced around a few diagnosis over the years but whatever it is, citalopram works the best and I have support from friends and family. I am stable.
My daughter has just started to exhibit some of the same traits I did at her age (13) she knows and understands about my MH problems, and has been affected by them, but only in the sense she has spent time living with her DGM when in the past I have been unwell - this has been a family decision, and once I had recovered enough that DM and myself felt that DD wouldn't be affected, she'd come home.
She's still loving and affectionate towards me, but she spends so much time alone, like I used to want to. She cries very easily, she has awful mood swings and she is pushing boundaries, getting into a bit of trouble at school for bad attitude and grades are slipping.
I know what I have just described is considered 'normal' teen behaviour, but it's just all so horribly familiar, it's how I started and I can't bear the thought of her feeling those awful and desolate feelings I did, and putting herself in danger the way I did sometimes. I'm terrified she's going the same way I did, that she's inherited or absorbed it along the way and that I should have protected her from this more.
Am I overreacting to teen behavior? Or should I be more proactive now in trying to get her some help?
Sorry I know it's long.

First of all, you need to be very clear that she is not you, she will not be repeating your life, she will no doubt have her own problems, but no one can predict how they will pan out just by looking at your life.

So any intervention or help needs to be planned around the problems she is actually having now, not something you fear will happen to her in the future. Be very careful here, as she may pick up on these vibes: nothing worse than living in fear of some doom waiting just around the corner.

If she is having difficulties at school, is there somebody she could talk to? School counsellor, pastoral support officer, trusted teacher, you? Is there something you can do together that lightens her mood? Would it be worth teaching her some techniques for controlling her moods (CBT)?

Thanks Cory, I try and not let her know about the worries I have regarding her MH as I've too thought about the weight of expectation on her. I'm hoping she doesn't pick up on the vibes, I try and keep it turned down.
She did speak with me before the easter break and asked me if I thought she needed to see the school councillor (suggested by her friend who goes and found it useful) I told her that if she felt she wanted to, and that it would help her then she could give it a go, but left the decision very much up to her, as far as I'm aware she hasn't gone, but only been back a week.
We share a couple of interests and do spend time together doing that. I tried CBT and didn't really get it, I'm probably not best placed to teach her, though I may as well make use of this sleepless night and do some research!
There has been a school incident recently that has triggered my worry more, not bullying or the like (she says she's not in the popular group but she's got a good group of friends) more she has been dishing out attitude to adults, without remorse and this is out of character - or was until recently, it's increasing!
I'm struggling to see if this is teen or MH, I think, because of my own issues - appreciate your comments, thank you.