@mika2020 I'm a dietitian and agree with the sentiment above. You can continue to run but if your goal is muscle/strength gain then training for races should be on the back burner until you are satisfied with your strength progress. Follow @littlelyssfitness on instagram, she is an endurance runner and a lifter and overall BA lady with a ton of free and evidence-based info on her page. @amandahowellhealth could also be a huge help
As for nutrition, I see a lot of people promoting calorie counting here. Calorie counting is a good learning tool, especially for learning the macronutrients that are in foods, but isn't a forever solution for most people. Try to use this time to learn to build meals that have enough protein,carbs, healthy fats, and produce (fresh, canned, frozen, dried, organic or coventional, as long as you are eating it, it truely is more beneficial to get it in your body then worry about the details!). The ideal amount of protein is 1.6-2.0 g per kg bodyweight for those trying to build muscle mass. Don't fear carbs either, get in whole grains, legumes, and root veg as these foods are nutrient dense and fiber rich. Yep this does include 100% whole wheat breads and whole wheat pastas. "Healthy fats" are the unsaturated fats typically found in plant oils, nuts, and fatty fish. Think pesto, oil-based salad dressings, tahini(a hummus ingredient), salmon and tuna.
In general, for building muscle mass you will need to be in a caloric surplus. However you don't need to be in a caloric surplus to gain strength. I suggest you really nail down your goals, prioritize either weight loss or controlled weight maintenance/gain, and consider a phased approach to your diet. You shouldn't be eating