i'm so sorry - i think this is pretty typical, but luckily, it sounds like your husband had every intention of making it work. so that's good.
i would advise you to not look for a 50/50 split of childcare, but instead look for a division of work (and time "off") that you can both handle. perceptions of what's "even" will always differ between you two.
finding specific responsibilities that he has to own, like getting up early one morning a weekend, regardless of what he planned the night before, or only leaving the house 1 night a weekend, to help with baby in the evening, is totally reasonable.
you may also need to point out that his generosity to his friends' projects needs to be cut back, so he can be generous and take good care of his family first. my bro-in-law is terrible at this: he helps everyone with their projects and lets his own slip.
and finally, i suppose you don't want to hear this, but he may be signing up for all these outings because he feels he needs them... while they are not OK in my book, you might be best off finding out how he feels about the responsibilities he has. (i just know that right now, preggo with #2, my hubby is doing way more than 50/50, but he is doing it because he knows i need him to, regardless of what's "fair". so when he wants to go play volleyball 2 times a week, i let him have his "me" time that he needs)
also - ask yourself what do YOU need? do you need more away time, "me" time? or do you need more "all together" time? i found with our first baby that i needed more all together time. it wasn't that i didn't want to be with the baby, but i wanted to be able to share the responsibility, and spend time together.