Breastfeeding & gaining weight/ not losing weight

So I have an almost 5 month old I have been breastfeeding. I feel guilty for having to give my son a bottle some days I don't make enough, I have to give him a 6 oz bottle of formula. I keep staying between 155 to 160 so I am usually 125-130 and this is my fourth baby. I have been stressed you know four kids and I'm in nursing school as well. My baby though I feel isn't getting enough of me because I can't feed him 24/7 some days. Il go a while and it's perfect like 3 days then I can't. I have been taking prenatal and fenugreek daily I was told by my lactation consultant and it has helped I wont lie even though for some it does the opposite. I dont want to be fat though I'm only 25 feeding my baby is number one I want to breastfeed I was never able to with any other babies so it's a wonderful experience. I just am so sad because I'm not enough and I will never look good ever I feel my belly is hanging over I am ok with being thicker and more filled out in my body but I am overweight and I can't work out because I live in a trailer park and I dont have a stroller or a baby carrier maybe I'm lying to myself but I'm so busy with school, cooking cleaning etc.... I just feel low.