You've answered your own question is saying you are risk averse and motivaion is an issue. In simple terms in sales you receive a few kicks in the balls. Yes you go down and it hurts but you have to pick youself up, dust yourself down and go again. And again. Oh and smile.
It's the only role where someone tries to undo your work and thats other sales people trying to get the order instead. I have always likened the role to painting a room and then person comes and changes the colour so you have to start again. In essence this is what your up against.
The economic climate has to be considered as well. Most companies are struggling to hit targets which means if you don't have the revenue the senior people will start restructuring the whole business and the easiests people to segment into income/expenditure are sales. We have suppliers who are condensing into better alined geographic and strategic structures which translates one sales person rather than three.
Based on those issues alone and your history, 20 years in the same role suggests you are relatively happy and content otherwise you would have moved on by now?
Work life balance is a threshold few get right but we are always striving for and having cash in the bank does not replace the missed life outside work. It really doesn't
The stress of a new role will be imense. If your not worried about that aspect then again it's questionable that the role is right for you.
Consider the future, is the business looking to have a more on line presence rather than employ sales people.In some cases where technical knowledge will be required there is a strong argument for sales people but condsider the platforms of webchats or more tech based people who are based in the office for a much lower cost.
it's an ever moving feast in sales and everthing is fluid and you need to accept these qualities and embrace them and take the benefits by thinking strategically past this months and next months figures.
That said if you can find your feet it's a great life but it's not the perceieved easy life many have and I'll leave you with the final thought which tells you everything you need on know. How many older sales people do you see?