Welcome msq!
Glad to hear baby arrived safely in the end but I'm going to tel you this now it is ok for you to feel bad, guilty, cheated and angry about it.
You are doing the most selfless thing you will will ever do by carrying, birthing and bringing up a child you are allowed to be selfish about some part of it - especially the birth.
I felt the same, no one I spoke to around me understood why or how I felt so horrible after my EMCS considering baby arrived safely...surely thats al that mattered?? Well it isn't all that matters! You matter and the experience matters.
As for wanting a VBAC in the future I cant see any reason why yo cant have one, but I'm no Dr! True cases of cephalic - pelvic disproportion are very rare indeed (often in cases of GD) more often than not it's a case of positioning that is the problem. You had an epi so I'm guessing you were laying on your back? When you lay on your back you baby has to move uphill to get out so unless they're already very low it's very very difficult for baby to move low enough to put enough pressure on the cervix to make you dilate and get the urge to push and then you have to find evergy to psh the little bugger up hioll and out - difficult.
Same happened to me baby was high so slow progress, he happened to be posterior too so bad position all around, I ended up with a drip to make me dilate and got an epi so was on my back - no wonder baby didnt move down!
Anyway - like I said it is very rare for babies to be too big, and no one can say that until it comes to the end of pregnancy when it can be estimated that baby might be too big -scans can be 20% out so if I were you I'd take that with a pinch of salt.
OB's can be very unsupportive, remember you dont have to see them.
You have a long way to go on your journey to VBAC yet, but you can and will be able to do it if you want. If when the time comes you do not have supportive MW/OB then find others you have the right to do so.
Spend time to forgive yourself for what happened, you didn't fail at anything the people taking care of you did, policy did, the circumstances did - you may have ended up with an EMCS no matter what but next time you will make sure you give yourself the best possible chance for a Vaginal Birth.
Don't let your EMCS be your undoing, let it make you stronger - you have survived the trauma and you will come out of the other side a more knowledgeable person who is clear about what she wants and gunning to get it!