You Need a Medical Check-Up

I don't know much about you from this inquiry, which is understandable on a venue like this. If you were in my office I'd be asking you for a brief medical history. We want to check out any physical complaints before we head to psychological or even spiritual problems. You have to deal with the 'denser' problems first. The physical body is foundational. 

You may think you know the reasons for smoking cannabis, and there are several, one of which is self-medication. I am left wondering if you had appetite difficulties before you began using because you heard that cannabis increases the appetite. There are undoubtedly unconscious motivations for using, and these are like 'sub-basements' in the 'building' which is the body. At any rate, even though I don't know how long or how much cannabis you were using, it can't be all that long if you're talking about your mom (I know people who have been smoking for 50 years). But what you are experiencing with your appetite does not sound like it is directly connected to cannabis use, not any kind of withdrawal symptom. 

Since I am a virtual counselor, and I am not a medical practitioner, I would urge you to see a medical doctor. Anorexia nervosa IS a serious problem, but unless you are restricting your diet intentionally, and exercising your ass off, AND a female (which you didn't identify but which I doubt), you have something else going on. Some kinds of ulcers make you sick when you eat, and other kinds make you sick when you don't, just to give an example. If your body-type tends to be lean and long (long arms and legs), you might ave a primarily Ectomorphic constitution, and Ectomorphs ( http://en.wikipedia.org/wiki/Somatotype_and_constitutional_psychology ) have a temperament that often suffers from high levels of anxiety, which can also ill-effect your appetite.

The bottom line here is to check out your physical health before proceeding with your mental health. This would be the advice of many different specialists in the mental health field. A sex therapist would insist on having the physical 'hard drive' checked before the mental 'software,' if you catch my drift. Before I treat someone with hypnosis for pain management, I'd want to be sure someone's headaches aren't caused by a brain tumor! The headaches aren't felt any more, but the tumor kills them! So, I insist on a letter from a medical doctor saying it's OK to treat for pain. Nausea is not a normal response to food. Please ask your mom (if she's still legally responsible for you), or you, yourself, if you're of age, to make an appointment with a physician ASAP.