From a child's perspective: I have two sisters a year apart younger than me, and I was expected to be The Big Sister and shelter them (read "free babysitter"). I was assigned the job of The Groundbreaker and was supposed show them how to interact with the world, when I was still wondering how to interact myself. Neither my sisters nor I appreciated this situation – I think I lost time I needed to learn how to just be myself, and my sisters chafed under my assignment that I control their behavior. We all still have issues in our 50's and 60's, and are not close at all.
I have a third sister who came along when I was eight, and I dearly loved being her big sister, because I had more maturity. We were inseparable when she was little.
So, close spacing may work fine for some kids, not so much for others. I've known adults who recall longing for less competition for their parents' attention or hating siblings with poorly matched personalities. There are simply no guarantees of sibling bliss, regardless of spacing.
I should mention that I've also known two women who were clearly brought into the world to meet the emotional needs and desires of their parents. Neither of them feels like a cherished person in her own right, both carry enormous anxieties and resentments, and both have been in therapy forever. One is periodically suicidal, and wishes she had never been born. Children are not toys, pets, rewards or possessions. They are singular human beings.
So your motives, and your husband's, are important. I'm not suggesting they are not worthy, because you don't give enough information for me to even guess. I'm just saying I hope you will consider carefully.
And with your sense that you could use a break, I think you have really answered your own question. Pregnancy, childbirth, and caring for babies make enormous demands on your body and soul, and it sounds as though those exhausting early months also leave you with resentment toward your husband. Please listen to your own needs carefully – your little ones need you to be the best, healthiest, happiest person you can be. That is in their interest just as much as your own.