Starting over is one of the few constants in DF, it's inevitable. Once you have your bearings, getting a fort "up and running" becomes pretty easy so you really have to start making your own fun. It sounds like you still have some milestones to cross, try getting your steel industry going and then maybe construct your first tower, or something.
Figure out what exactly is most appealing about the game to you and then go crazy with it.
Some people like megaprojects, constructions, difficult embark sites, or other artificial constraints. Personally, I have the most fun designing fortresses. My current fort, for example, has three separate mountain peaks linked by enclosed sky bridges, an incredibly lavish memorial hall that leads to my king's mountain top throne room, and underway is a giant magma filled statue that I'm carving out of earth (rather than building).
There's so much to do in this game and my projects are honestly peanuts compared to what some are able to pull off. Keep playing and you;ll find your niche!
[e]the wiki has a great list of common projects. It's a good place to pick something from, or just to browse for ideas:
megaprojects