This is all quite raw for me OP as I was in a similar position to you and just stopped breastfeeding DC2 a few weeks ago. So I'll be totally honest, in case it helps!
Breastfeeding DC1 was a nightmare, she lost a lot of weight and ended up back in hospital with jaundice and dehydration. It totally ruined the newborn days for me. I combi fed for a bit then quit around 8 weeks and it was totally the right decision.
When pregnant with DC2 I thought I would FF pretty much from birth, but she actually took to BF a bit better than I was expecting. I was terrified of her losing weight like DC1 had so I gave a bottle of formula a day from the start, then cut out most bottles by about 6 weeks.
I don't know why, but I just didn't find it got easier though. At the magic 8 week mark it was actually harder and by 10/11 weeks I was really struggling. She would be really fussy and sometimes refuse the breast, or breastfeed just for very short periods then come off crying. No real BF support or HV clinics but I was weighing her myself at home and could tell she wasn't gaining much and it was hugely stressing me out, especially after my experiences with DC1, so I ended up combi feeding and then switching over to FF totally by about 14 weeks.
Am I still glad I tried? I don't know. Probably because I'm sensitive about it, I feel like everywhere I look, people are talking about how wonderful breastfeeding is and how they BF their children for two years each and it does make me feel like I've "failed". Again. I've had to hide all the mum FB/whatsapp groups I'm part of as they seem to be full of people experiencing similar issues to me who are battling through rather than "giving up" like I did.
I sometimes think, if I'd just made a positive choice to FF from birth would I feel better about it? In the same way that some women opt for an elective c section after a traumatic birth, to feel a bit more in control second time round. There is no way of knowing but it does make me think.
As far as breastfeeding around another child, mine is a bit older but when it was going well it was ok. When it wasn't going well it was a real struggle, I'd find a lot of the tips for fussy feeding just weren't practical, like going into a dark room and playing white noise etc.
My advice would be to try and process your feelings from first time round as much as you can, and be honest about why you might want to BF second time and how you will feel about it if it doesn't work out as you planned.
I'd try and block out the people quoting random studies and reasons why they loved breastfeeding as it's kind of irrelevant really. You've done this before so you know all about what the pros and cons are on paper, and how that can differ from the reality.
Good luck with it all. In a weird way this has actually really helped me to process anything so if nothing else you've helped out another mum by starting this thread 
