Can being full off of food effect a mans erection?

Depends. It depends on how full you mean. If you just had an episode of binge eating you might not feel particularly sexual. Also if the meal included alcohol your sexual performance could certainly be affected. I see that you're on amlodipine. Male sexual dysfunction happened with this medication less than 1% in placebo-controlled trials, but between 1% and 2% in all multiple dose studies.
Probably not. Having a full stomach should not affect your ability to achieve or maintain an erection. There can be many factors, from your mental health and degree of stress to medical conditions, such as diabetes or vascular disease, that can affect your erection. See your primary care provider, and a urologist if necessary.