I Am A Blotted Male, Age 64. I Only Feel

I am a blotted male, age 64. I only feel like eating once a day. I always feel so bloated and it's hard to walk due to some damage to my upper disk. MY ford f-150 was hit in the rear by a dodge doing 60mph. This was in 1996, now I suffer sever back pains and can't walk too far a distance. Recently for the past four days I have noticed that my stool is 'BLACK' really 'BLACK" Noticed excessive stomach blotting. Little discomfort. What do I do?