Firstly, watching portions is a huge improvement. So while you might be feeling a little stuck right now, keeping your portions in check is a skill to keep for life. Be proud of yourself for taking that step forward! Now, it's just time to take the next step.
If you're aiming to choose healthier foods, I'd suggest starting with the
Good Health Guidelines (often referred to as the GHG). If you want to make those steps even smaller, then you can start with one Good Health Guideline every week or so until you're covering all of them.
So, the first week you aim to drink 6-8 glasses of water a day, and check them off as you go. You add this to watching your portion sizes as you have been already, and tracking all you eat.
The next week you aim to get in at least 2 servings of dairy (in yogurts, milk, cheeses) along with the 6-8 glasses of water, and continuing to track.
The following week you start looking at your servings of fruits and veggies. You can add a couple in a day for starters while working with the rest of the plan.
Onwards and upwards from there. In a couple of months, if you keep watching after the GHG, you'll be eating vastly healthier. From there you can change even more things to your style of health.