I'm in the same boat as you. I've got a six month old, and I work 2 mornings a week during which time my daughter misses one, maybe two feedings. She's an exclusively breastfed baby.
Here's what I would suggest that you do:
1) Don't worry about your baby starving. He won't in the relatively short time your gone. He may just decide to wait to eat until you get home. So be it. Your baby IS going to be okay.
2) Plan to pump at the same time every day, so that your body gets used to it. If your son has a longer stretch of sleep at night, plan to pump somewhere in that time frame. For example, my baby pretty reliably sleeps from 7:30 to midnight, so I try to pump around 10:00/10:30 right before I go to bed. However, I've also heard of women who pump right after the baby's first feeding of the day when their milk supply is at a peak. It doesn't really matter too much when, just pick a time that you can be consistent at, and try to do it every day. This will help you build up a supply of milk, so that you're not in the position of frantically trying to pump the night before you go in to work.
3) When you come home from work, you're probably pretty full of milk, even after you nurse the baby. That's another good time to pump. I usually end up pumping at that time as well, as I've got more milk than my daughter is able to drink.
4) (I'm not sure if this exactly appiles to you, but...) I am told that my daughter is not particularly amused to be drinking her milk from a bottle, but with a little patience on the part of the person feeding her, she will usually take it. However, she won't drink from a bottle if she knows I'm around. So, encourage the person trying to feed her to just be patient, perhaps squeezing the bottle's nipple to get a little milk out to tease your son with.
5) One more thing. Do the best you can to relax while pumping, as it will help your milk to let down and flow better. Put something funny on the TV, and watch it while you pump. Massage your breast a bit before pumping. Take a deep breath. Do whatever you need to so that you can be as relaxed as possible. Remember that everything is going to be okay.
Good luck! This too will work out.
~ E.