I have cancer and I don’t think I can fight it anymore. Idk what to do

I’m on my second round if it’s at the point where all the side effect meds aren’t doing anything. I feel super nauseous all the time (they are giving me max everything) I literally feel like I’m being poisoned. I have 41/2 more rounds after this I can’t imagine it getting worse than this. I have so many other problems in my life outside cancer I just don’t know how I’m supposed to fight this. What do I do? I’ve have had chronic health problems my whole life and I’m just at a breaking point that I really think I can’t beat this.