L.O.
I was there.. my boy /girl were 18 months apart .. and it is hard.. very hard.. and harder in the winter when it is more work to get everyone dressed to go outside..
I would call a local school district see if they have playgroups.. I went to a playgroup at a local school with both kids and it was my sanity.. and playgroups in a school building are better.. the kids had the gym to run in and great toys.. and the teacher led the group and planned the activities so it wasn't a free for all.
look for kindermusik classes they are great... some are expensive.. others are not... (parks and rec for the local cities are the best source for cheap activities.. some community centers have playrooms for little ones..