Feeling like it’s ending...Advice???

My husband and I have been together for 12 years. Married for the past 4 1/2years. We have a beautiful busy 3 year old and this year has been the hardest yet. I’ve had nothing but health problems for over the past year- this year being the worst. Drs have ran numerous tests- can tell me what is abnormal but still no idea what is causing my problems. This year alone I have had a lot! I had a laparoscopy- dr thought I had endometriosis(said it even looked like I had it when she went surgically but biopsy result were negative). Also found out I have severe pelvic congestion syndrome which is causing my pain in that area. So I did get an answer there. Fast forward to my asthma getting worse- pulmonologist thinks has to do with acid reflux and started me on new meds. Next month after that I injured my rotator cuff at work- about the same time the pain was getting almost unbearable,as my arm was beginning to freeze(went to 2 different ERs trying to get pain relief), I began to have heart problems was taken twice by ambulance and landed in the hospital a week. I ended up being out of work for several weeks and did 4 month of PT(dr wouldn’t operate on my shoulder as it was not a complete tear). Then started having severe stomach pain- dr concerned about my gallbladder so here we go to the ER again. ER dr dismissed it as severe gastritis. Follow up with regular dr- not believing ER drs diagnosis so now I will be going to have a scope done next month. On top of all of this already our daughter started school this fall so we have both been sick a lot (my immune system sucks esp with some of the meds I am on). I understand it is a lot. It’s been a lot for me. It seems like all we do anymore is fight. He gets so upset when I am not able to take care of things and has been so short fused. When he is doing ANY house work he throws a fit- throwing things, swearing and making a scene about things. I can understand some of his frustrations but at the same time I feel so torn down. I feel worthless. I feel like we have lost our partnership. Don’t get me wrong-he has been the one taking me to the ER and stayed by my side when I was in the hospital. In those moments he was amazing. But those moments are farther apart than ever. I want to feel better and I honestly do the best I can. I’m just feeling so discouraged and hurt. I feel so broken and torn down. I feel like our vows and what we once were are not standing strong and are ready to collapse. I love him- but anymore I feel like his moods are like a rollercoaster- more down than up lately- and after growing up with a bipolar father who refused help for almost 20 years- there are standards I have that will result in me leaving if this continues snowballing. I want to see this marriage work. Generally we would talk this out. He would apologize and we would be better for a while. Now if I’m lucky-he will apologize, and seem sincere,but then it doesn’t take long that he goes right back to the same crap. Anymore trying to talk to him just leads to more arguments. I am at a loss. I know marriage is hard but I never expected this. I’m beginning to think this relationship is heading in a toxic direction. And if he isn’t going to be as willing to work with me through all of this, I will do it myself or find someone else who will! I feel as though he is bringing me down! Sorry for the long rant and thank you so much if you have stayed and read it all. Am I wrong in dreaming of a happier partnership? Any advice?