I would ask them more questions to clarify why they are mentioning a c-section. I know my SIL had 4th degree tearing and they told her she can never give birth naturally again because she was a real mess and her recovery was very complicated. I don't know a whole lot about tearing - I had a second degree tear with DD1 but didn't tear at all with DS (I felt normal the day after he was born - no pain or anything) and I had a c-section with DD2 and my recovery was long and difficult.

From personal experience, I would recommend doing everything possible to avoid a c-section because I think VB are a much easier recovery, but since you had complications with your first, I would try and collect as much info from the ob as possible to help make the decision.

I would find out the risks of having a VB after a third degree tear, are they recommending a c/section to you based on your own individual medical history or because it is standard procedure, write down anything you can think of and talk to them about it. Get them to talk you through a c/s too. It might help you get some info and if you decide to go down that path you can be a little more prepared for it.

I don't know about severe tearing, but it is common in second and subsequent births for tearing to not be as severe - often tearing happens severely when births are quick, but there are things you can do to prepare your body and minimise the risk of tearing. I would look at those things too.

Good luck with everything. I hope you can find an ob or midwife to sit with you and talk through your options in detail so you can make an informed choice.