Troubles with Calorie Intake

Hello,

I [30, M, ~140lbs] have been wanting to get into building some muscle for a long time, but I have always had a really hard time with one aspect of it. I can not, for the life of me, eat enough calories. I have an extremely hard time even just keeping down 8oz of food. It has been like this my entire life and I have been trying to break this limit for years now.

Are there any tips or tricks to get around this? Or am I just kind of screwed?