First of all, congratulations on becoming a runner! Running can be a great tool for weight loss as well as getting and staying in shape.

In regards to how much you should be running, unless you are training for a particular endurance race such a half or full marathon, I would suggest you run no more than an hour. Instead of increasing how long you run, a better choice would be to gradually shorten your walk intervals. Once you are able to run without taking walk breaks, you may want to consider adding speed work and strength training to your weekly running program. Adding different intensities to your workout program will help prevent the dreaded weight loss plateau from happening.

When trying to lose weight, unfortunately exercise is not the only answer. It’s very important to focus on both diet and exercise. From the sounds of it, you have already found a consistent exercise routine, which is great. The next major focus then should be on what you eat.

Something to be aware of is that running can increase your appetite, so you will want to make sure you do not eat extra just because you went for a run.

Here are some general tips to get you started in terms of changing your diet:
-Eat mostly fruits and vegetables.
-Limit sugar and junk food intake.
-Stay away from sugary, high caloric drinks like soda and fruit juice. Opt for water.
-Include lean protein with every meal.
-Eat carbohydrates in moderation.

Don't be tempted by a fad diet either. For lasting weight loss, a healthy diet that you can keep for life will allow for lasting weight loss. In order to do this, make small changes slowly. For example, first, cut out soda. Then start adding a vegetable to every meal. Small, slow changes in your diet will increase the odds that you will maintain this particular healthy eating lifestyle for good. This will also ensure that the weight you lose in the process will stay gone.

Sources:
https://www.webmd.com/diet/features/diet-vs-exercise-the-truth-about-weight-loss#1
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3406229/
https://www.popsugar.com/fitness/Why-Running-Doesnt-Help-Weight-Loss-23050499