What you're going through is so normal. Your hormones are raging, you are exhausted (from sleepless nights and from having been through a hard pregnancy), you have some PPD, you're no longer pregnant and drawing attention for that, and you're stuck in the daily routine of diapers and laundry and ordinary life. The appointments no longer focus on you, but are about your baby's milestones and typical well-baby moments. It's not at all selfish of you to miss all the people who cared about YOU and your body and your feelings!
You may even be affected by the shorter days and the coming of colder weather which makes outings more difficult especially when you have 2 kiddies to get into jackets and car seats and so on.
You're looking for someone to understand you, and pay attention, and your husband is into the routine and seems inattentive or unsympathetic. Part of you may want him to just "know" how you feel, but ask yourself if you are being so competent with the parenting that you're giving an impression that you are managing just fine. If he thinks this is a purely hormonal depression that he doesn't understand or which can only be managed with medication or counseling, he may be unaware that you need much more from him.
When I was counseling couples considering ending their fertility in some way (either vasectomy or tubal ligation), our advice was always to make the decision after considerable discussion and never under the pressure of problem pregnancies, hormones, exhaustion or other issues. So unless either you or your husband has done anything permanent, I'd strongly suggest that you defer the decision and avoid discussion of it entirely. Postpone the discussion for 6 months minimum, and maybe for a year. Figure out all these other things first without any thought to whether you'll want to have another child in the future. Deciding not to have any more children is a huge step - and even a good decision to be satisfied with the current size of a family can leave one or both parents with some wistful feelings. For some people, a family is complete with 1 child, or 2, or 6, or none. There's no magic. What you are feeling also comes along for many women when nature ends their fertility in menopause.
So lighten your load as much as you can - no more talk or anguish right now about "a third child or not", more communication about what you need to feel special, more focus on how we or society treat moms as "boring" and "old", the role of body image (when our post partum bodies aren't so young and flexible as before), and maybe some counseling to help you find the joy and respect women deserve for all that we do.
Good luck! You'll figure it out - but not all at once.