Hi Sarah,
I had my two 14 months apart the same week I stopped taking mini-pill, (I was BF too - DS1 was 5 months) but I did not have the pressure of DP not wanting any more kids. He wants as many as I'll have so it's basically up to me. I did feel a little isolated when they were growing up because I didn't drive and my bff and I had stopped talking but I coped until I found support with playgroups. I didn't have trouble with my body returning back to pre-pregnancy weight. I do still have a little bit of lose skin from stretch -marks but I worked hard and ate healthy which also helped my emotional health.
I think you should discuss it with DH and find some support in your area so that you don't feel so isolated. There is nothing worse than feeling overwhelmed, under appreciated and isolated when trying to raise kids so try and look after your mental health first and then the rest will fall into place. I don't know if it affects BF but you could look into alternate methods of contraception such as the Marina device. You definitely need to share with someone near you that you are not coping as well as you should so that they can help you (whether it's hubby or a mother's group, family etc).
I hope this place can be a source of support for you as well.
Good luck!