My Chihuuahua has confidence issues and also a dietry question

Question
Hello.  I have a 2 year old Chihuahua - Skip.  I got him when he was 7 weeks old, and at the time he was a confident, carefree little pup.  When I got him, literally everybody I knew, wanted to meet him - and did, and so was well socialised, meeting kids, and adults, males and females on a regular basis.  He was around 5 months old when new years eve arrived.  Someone in my house opened the door around midnight, and at the same time several fireworks 'exploded' in the air.  Skip lost control of his bladder and was physically shaken by the noise.  He calmed down after a short while, and seemed OK.  Since that night hes now nervous of literally everything.... people he doesnt know, other dogs, the hoover, (obviously) loud noises, even quite noises eg, opening packaging to something like a bag of treats where the plastic bag crackles as you open - if hes anywhere near by he'll run off and sit over the other side of the room ---- well until you show him the treat!!  Its upsetting to see him so nervous of everything, yet the people he met before his trauma he loves to pieces, and is otherwise a completely happy, healthy, playful little dog.  Ive enquired about animal behaviourists, but I cannot afford their prices as much as I want to correct this behaviour.  I introduce him to new people every opportunity I get, but this also becomes a bit of an issue, as, due to his lack of confidence, he'll bark constantly (whilst wagging his tail), and has on occasion, pretended to snap - but thankfully never made contact with anyone.  People laugh because hes a chihuahua and think they can ignore his fear and try to stroke him anyway "cause hes little" but he weighs in at 8lb, and regardless of his size, I never want to be in a situation where he does bite someone.  Could you suggest any techniques I could try to help him build his confidence?  I desperatly want him to his confidence back in people and everyday noises.  Skip has a younger brother (his half brother) who is 4 months younger than him - and is the (much smaller), dominant male.  They get on like a house on fire so no problems between their relationship at all but thought it was worth mentioning.  There are also no children in his household. Also, just a minor question Skip has a passion for peas (cooked) and eats quite a portion whenever we have them - Is this ok for him?  Sorry for such a long post - I look forward to any comments or suggestions you might have.

Answer
Peas and veggies are great for your guy :)
I'm sorry to hear that he had such a traumatic event. He's suffering from post traumatic stress. People never realize how shocked dogs can be when things like that happen. And there are several periods in puppy hood when trauma can REALLY affect their behavior. I think you unfortunatly hit upon one of them.
Don't baby him when he acts afraid , you say "oh baby it's ok nobody'[s going to hurt you" he hears, "be afraid good dog for acting like this " and you reinforce his behavior.
Get him involved in an obedience class (yes I know but do it anyway LOL)
power walk him thirty to forty five minutes every single day EVERY SINGLE DAY. Use a halti if you have problems controlling him on lead just give him time to get used to it before walking him on leash with it. Keep him at HEEL at all times and ignore him completely on the walk unless you need to give him a little tug as a correction.
Tired dogs don't have as much energy to be nervous. Wear him out at least three times per week whether it's walking until he's ready to plop down,playing fetch if he will, whatEVER it takes run his little legs off three times per week. Give him lots of interactive toys and switch them out often. When he behaves irrationally correct him. At least with a loud CHH noise and a tug on leash or a little push with your cupped hand into the side of his neck. NOT painful just a push. Reward him anytime he for a SECOND engages things he's afraid of with a calm attitude. but you have to be FAST. Use a clicker if it'll help you.,
Go to alpha boot camp on the web and read and learn the ways to establish and maintain pack order in your home. This will give him more confidence in you as a pack leader and because of that he will feel safer and more secure. Even little dogs need to know where they stand in the pack and he does NOT need to worry that he might have to be the leader. He shoul feel confident that you will protect him. Take him everywhere with you anywhere you can, post office dry cleaners wherever and do NOT reward nervousness or fear signs with any kind of attention at all. Be confident,. be natural, be assertive,. do not  gush over him or try to comfort him, he doesn't understand that and gets the wrong message. Changing your attitude will do wonders toward changing his :)
best of luck
Cindi