Luvvy, I am so glad that you're here. First and foremost, you made a huge step toward quitting just by coming here and sharing your story with us.
Secondly, set a quit date... it can be as soon as you want, or as far away as you want... but whatever it is, stick to it! I recommend setting a date that is AT LEAST two weeks from today, simply because you need time to mentally prepare yourself for what you're about to do.
Different people handle quitting differently, and like with most things, you need to determine what is going to work best for you. Personally, I would recommend that you buy the patches and when your quit date arrives, stick one on!
Quitting cold-turkey can be absolutely torturous and ultimately lead to a very disappointing failure. It does work for some people, but I don't think it's the best way to go for most. (JMO)
As for the weight gain, instead of shoving food in your mouth, drink a glass of water. Not only does your body need it, but many times hunger pangs are actually a signal for thirst. Drinking the water will curb your need to eat something. Get on a healthy eating regimen and stick with it... that's something that should be done whether you quit smoking or not.
Psychological effects... this is a tough one. People are addicted to cigaretts for different reasons, and in different ways. Regardless, I think that having a positive mental attitude is going to kick 99.9% of any psychological issues in the butt. (Pun intended, dorky as it may be) Keep yourself busy. Most importantly, try to change around your daily routine that usually includes a smoke. (For example, if you have a cup of coffee on the patio every morning with a cigarette... now have your cup of coffee inside by a window.)
I'm not going to lie to you... quitting isn't easy, even when you have things like the patch or pills. However, it IS possible to succeed, and you CAN do this. Put your mind to it and don't give up. If you fall off the wagon, we'll be here to pull you back on it.