I need to gain weight but carbs make me feel bad

Hello everybody.  I have struggled with an eating disorder for as long as I can remember now.  I restricted my food intake, and with a fear of bread and gastritis which kept me from eating a lot of fruit I kind of became ketogenic after awhile without even meaning to.  I now weigh  68ish at 5'3.  This is really bad for me and I know I must gain weight but my problem is carbs just make me feel bad mentally.  I don't know why.   I feel so much better when I eat low carb.  I can think better and clearly.  I feel motivated.  Even when I gain weight I end up turning it around and going back to a high fat low carb diet because I feel so much better mentally and emotionally.  I don't know how to get past this :(  Its as though after all these years living this way my brain cant get adapted to the carbs anymore. Does anybody have any advice?