You have worked hard to breastfeed, and you have anxiety about returning to work. This is normal, so, respect these normal and healthy feelings.
First off, i agree with pp. 12 weeks is 4 weeks away-think how much your baby has changed in just 8 weeks. A 12 week old is different than an 8 week old.
But let's say your right and your baby is going to be just the same-or even more fussy. If rearranging your lives so you can stay home or be home more, or bring baby to work, is not an option, then you and your husband will need to make this arrangement work.
What is your husbands plan if he does not 'believe' babies can be overfed with bottles (it's just a fact, not an opinion,-so it's like not 'believing' a gasoline engine would be ruined if you ran it on seawater.) But whatever- if he won't try paced bottle feedings and other comfort measures or handle diaper change crying, what is he going to do? Over feed her into a coma? Let her scream all day in a soaking diaper in the crib? I doubt it. Maybe he-and you-would benefit from a couple practice runs prior to the return to work so he can discover what it's like to take care of baby all day alone, and you can gradually gain the confidence your baby will be properly cared for and attended to-but maybe not in exactly in the same way you would do it.
We all need parenting tools/suggestions to get us started, and from that we and baby figure out our own way. So give him your suggestions, print out the linked below articles, maybe even try bringing him to a LLL meeting or to chat with a LLL leader or an IBCLC. I like pp ideas for a daddy baby carrier- you can help him research infant carriers and see if there is one he would be comfortable with, etc. But then you will need to give him the space to figure out his path. What if your roles were reversed, and he worked while you stayed home-and you did not breastfeed? You would figure it out. He can too.
How much expressed milk will baby need -
http://kellymom.com/bf/pumpingmoms/pumping/milkcalc/
Paced bottle feeding and milk handling
http://www.llli.org/docs/00000000000...fyour_milk.pdf
And
http://kellymom.com/bf/pumpingmoms/f...ottle-feeding/
Fussy baby ideas
http://www.llli.org/docs/00000000000...ybabyideas.pdf
For dads
http://www.llli.org/docs/00000000000...t_partners.pdf
ps the dr.'s sears books & articles often have good suggestions for dads.
www.askdrsears.com