I am having B-Cell nonhodgkin lymphoma, got four rounds Rituximab, now having low Hb 7.6, bedridden for 1 mo.?

What should I do for increasing my Haemoglobin level ?. I am bedridden since last month. I was treated in ICU for infection that spread throughout the body after the fourth round of Rituximab . Now the infection is gone but cant get up from bed without help. Cant hold even mobile phone by hand. I have nausea and dont feel like eating much food. I am also suffering from constipation.