One thing you could try if you haven't yet is share your issue with your son and try negotiating a set of rules that could be okay for both of you.

There are two prerequisites. First, you did not mention how old he is but I can only hope he is older than six-seven years. A younger child has close to no chance understanding that you might see the world differently than him.

After five years, children's cognitive capabilities typically reach a maturity level that allows them to understand false beliefs, aka the concept that person X could experience the world differently than person Y (if you are interested in developmental psychology, look for the "sally-anne test"). Without this cognitive capability, your only option is to be patient, give him as much love as you can, and take time for you when you feel you are becoming overwhelmed.

The second prerequisite is to "reach" your son at a moment he can mentally ingest this information and is not solely focused on satisfying his needs. Typically, you should not try entering this negotiation during or right after a "talkative episode." Something in the likes of: "Daddy needs to have a conversation with you, but you will need to sit a listen to what I say for some time. I understand you have many questions to ask so I will let you tell me when it is a good time to have this discussion."

When you have this discussion, I would recommend using a negotiated problem solving scheme:

1. "I would like to share something I feel about us, are you okay with that?"

2. "When you do X, I feel Y and Z. It is doing that and this, and it is very difficult for me. Sometimes this makes me do X and Y, and I don't like to do this and I am also quite sure you don't like when I do that. Do you agree? Do you feel these moments?"

3. "I would like us to find a set of rules we can follow to avoid overwhelming each other. I don't want you to stop asking me questions at all, this is not what I am asking. I love you very much and sometimes I am worried that when I am tired or stressed I could not give you all my attention. Do you have any ideas how we could do that together?"

4. "How should I let you know I need some recharge myself?"
5. "How should you let me know you feel the need to share things with me?"
etc.

Of course, chances that this will work the first time are close to zero, so adapt your hopes. You are the adult, the responsibility falls upon you to find the patience and dedication to bring you both to a better place. Also, aim low during your negotiation: remember that your objective is to make things better, not perfect, and advancing one step is always better than nothing.

Like someone recommended above, your son might need professional help but don't underestimate the fact that you need help, too and probably more than he needs help. A child usually needs parents to show him/her unconditional love and to show up, not much more. It is very likely that you are being challenged to find resources deep in yourself that you may not know how to reach. If you are not feeling actively supported by your closer ones (e.g. spouse, friends), I would advise seeking support from a professional or a local support group. You need to be at your 100% when you are with your son and it is your responsibility to take the necessary steps to achieve this state of mind.

Anyway, I root for you and the simple fact that you shared your experience already shows you are doing the extra mile to find answers. I am convinced you will find them, good luck :)