Don't feel bad for feeling scared to deal with your trauma... its often as scary, if not scarier, having to go through it again than when living it to begin with. It's like taking the bad in your past and making it your present... fear is pretty natural and expected. Just accept though that it is your past when you deal with it in your present. Now is not then... now is what you make it to the best of your ability.
Oh, and he used to rape me, I suppose, as I would say no, or to stop but he kept going and made me lay on my front so he couldn't see me crying. I guess I could have tried harder to kick him off but I'm really small and he was huge.
Don't own abuse please, its not healthy. He raped you, accept it for what it is and don't make excuses that put any of that guilt upon you. He owns the guilt of raping you, not you.
I'm scared that when I finally do let down my barriers, which I'm trying to do, at least in therapy, that I'll end up just crying all the time or flying off the handle at everyone, or not being able to go to work, or care for our little boy!
Some or all of those things are realistic. Before embarking on trauma therapy you MUST put in place measures of stability. For example, before you even open pandoras box for trauma (once you start, you can't close the lid) put realistic measures in place. Crying -- nothing wrong with that. A healthy means to express the negative feelings, just don't allow yourself to live within it. Flying off the handle will be expected -- so put strategies in place, such as when you do it, have a place or activity you go and perform to chill out, calm down, then come back and make any apologies needed. Not able to go to work -- very possible, so ensure you have plenty of leave available first. If that means talking with your boss and saving leave up for a year in case you need it, so be it. Tell them what you're doing so they aren't, i.e. I need to do some trauma therapy for some past issues (don't give details) and may need to take some days off at times when I get completely overwhelmed. Also... book therapy sessions for Fridays to use the weekend as part of your recovery. If by Sunday night you're not fit for work, call in and use some leave. Your son... realistic also as you may just want to stay in bed. Again, parental help, grand parents, so forth... put them on notice you may need help. Even help at home to clean, do washing, so forth.
What is it like when you start dealing with the trauma properly?
Your life is going to turn upside down at times. That is the realism. It is short term pain for long term gain though, so don't think you can put it off, because it will only get worse if left un-dealt.
What happens when you start feeling stuff again (I'm completely numb most of the time?)
It has positives and negatives.
Is there a period where you turn into a complete head case?
Absolutely... it can last weeks, months, years... but will it really be any worse than the continued suffering you're experiencing?
I'm scared to take the plunge!! But knowing what may happen can give me opportunity to prepare as I need to take the plunge!
Fear is normal... accept it and use it to motivate you, don't let it control you so you avoid facing what must be faced and dealt with.