For FULL healing? Yes you probably will - but as the others have said - start with what is at the top and slowly work your way thought it all.
You don't have to do it all at once, and it takes time (often a lot of time) to develop a trusting working relationship with your T.
I think it would be a huge mistake to not ever talk about your childhood abuse. I'd encourage you to be HONEST with the T when you see them - tell them you have childhood / other trauma but you are fearful of approaching that stuff right now. Discuss your fears around what talking about it might bring up. Its important to just be honest, and up front, as well as to let the T know what you are ready to face and what you aren't quite ready too. A good T will NOT push you to reveal too much too soon; a good T wil encourage, support and guide you, but never 'force' you to 'go' where you just aren't quite ready too.
Why is it important to not ignore past abuse? Because you KNOW it's there - and it will still be affecting your life, albeit it in ways you might not be fully aware of yet.
I had years of therapy from age 18-late 20s. I truly felt I had worked through ALL the past abuse and how I felt abut it. I had come to a place of acceptance, understanding, and embraced life - I could even see how all the bad experiences I had had, helped me to be the strong person I was. My Mum was my main abuser - I witnessed her sudden death aged ten years old; I had come to such a place of acceptance I changed my Will so that I would be cremated and my ashes buried with her. I even saw the 'positive' in having to walk in the room exactly as she was having her fatal heart attack.
But - further trauma a decade later suddenly triggered up a LOT more abuse, and a LOT more flashbacks and long buried emotions I had never experienced since the time of the abuse. My PTSD was back, and worse than ever before. I've had 3 years of PTSD and severe eating disorder relapse since. I have just about lost everything I had worked so hard to gain after my first major recovery from PTSD, and I don't even think I'm even hallway into the pain and trauma yet.
IF you have had PTSD once, you are much more likely to get it again, if some other trauma happens to you - it won't be coincidence you have PTSD from another trauma in your life either - so if you know you have other abuse / trauma issues that are 'there' then I really do encourage you - at SOME point - to fully explore them. Not doing so, you might heal form the latest trauma you have gone through, but the other stuff won't ever be far away, and WHAM, up it comes at some point in your life ;(.
SO please at least tell the T you do have other abuse from childhood, and tell them very early on - even if you cannot go into details, just say you can't quite yet - but whatever you do, don't ignore it.
You're stronger than you think, you can do it.