Running advice please

I used to run regularly in the past, about 4-5 times a week. I am getting back into it but I need a plan. I can run 5k but I am very slow and some days it's a struggle.
Will it get easier if I just keep at it or would it be useful to do a 5k programme? They start very slow with 1 or 2 min of running followed by 1 min walking. As I can already do the whole distance, I find it frustrating to go this slow.
I also do strength training with kettlebell and body weight exercises.

Look up Hal Higdon's training programs - they are very good!! Maybe you can find a road race nearby that can be your inspiration/motivation also!

Here's his novice 10K training program and novice 5K training program

Some people repeat the C25K programs to work on their speed. Even though you can already run the full distance, try doing the intervals at a quicker pace and use that to build up your speed. I don't know if you want to go all the way back to week 1, but you can start wherever you want.

I ran 3 miles a day at my anaerobic heart rate. I went from running a 15 minute mile to running a 10 minute mile in 30 days. You can do a google search on Mark Allan heart rate to figure out your anaerobic.

Thank you all for your replies.
I will have another look at C25K and probably start somewhere in the middle.
Do you all use heart rate monitors? I usually pace myself based on my breathing but HR probably gives you better idea of how fast you should go.