Great job on the first bike. This will allow you to enjoy the bike for a long time. I started on a full carbon tarmac (soon after getting rid of my mid-90s trek 1000 after a month) and have enjoyed it so much. I started in a similar fashion as you and now I enjoy racing. I lost 20 lbs and have kept it off and on my way down with the help of dietary and sleep changes. All you need is TITS (time in the saddle). doing longer rides and will help you build your base.

As for the pain, are you putting a lot of pressure/weight on your hands? You shouldn't be, if that's the case. What kind of shorts are you using? I've found that better quality bibs/shorts help a LOT. I tried using Pearl Izumi shorts and now I won't touch them for anything over 10 miles. Try better quality bibs with brands like: capo, castelli, sugoi, and other bibs. You may also want to try a saddle with an open middle section or a saddle with a different width.