E.T.
Ok - so just to reflect back what you said.
1. Your husband has a good job.
2. He's also a good father.
3. You don't want him to travel, although his job requires travel.
4. If he travels, you don't want him to have fun because you're not having fun.
5. You're making yourself and your husband miserable because you expect him to entertain you and ensure you're not lonely.
You realize how petty that sounds, right? Do you really think your husband has invented a job that requires tons of travel just so he can stick you at home and miss important events like your son's birthday?
Sorry to be so harsh - but you need to grow up about this. Your husband would probably LOVE to be at home more than he is. Endless travel is not very much fun, even though it seems to be from the outside. And your husband is not responsible for your happiness - you are. So buck up, make some new friends, host play dates, invite friends over for dinner when your husband is gone, and try to get back to being the supportive partner/wife that you were before.
Or, you could keep whining about being lonely to your husband, tell him how much he's letting you down by having to do his job, and see how that pans out. Seriously - what do you expect to gain by fighting with him? Do you want him to change jobs to one where he doesn't need to travel? If that's the case - be open and honest and tell him. Just don't take out your frustrations on your husband just because it seems like he's away having fun while you're at home not.