What Causes Abdominal Bloating And Water Retention In Body Post Aortic Valve Replacement?

Hello. I m a 36 year old male with heart disease (radiation induced). I am vegan and up until surgery, I exercised regularly and weighed 153lbs. I had my aortic valve replaced 25 days ago via a median sternotomy. While I am still in a great deal of pain I have two other larger concerns. 1) Severe bloating - I constantly feel full and uncomfortable no matter if I ve eaten or not. It feels this always affects my ability to breath properly and catch my breath at times. 2) Water retention - I still weigh nearly 20lbs more than I did pre-op. My doctors did say that per a recent ECHO, I still have some water around my heart (pericardial effusion). They believe this will go away over time with the Lasix medication I am on. I addition to the Lasix, I am trying to consume as many natural diuretics as possible as well. Any advice you could provide would be greatly appreciate. I feel that my healing and recovery are at a stand still. Thank you.