clicky locking knees after running

[beginnerrunner]

I am training for a few running events but my knees have started to click/grind and lock, particularly after running. I have started slowly and built up to a week that looks like:

Monday rest
Tuesday swimming
Weds 3 mile run walk
Thursday 2-3 miles run walk
Friday rest
Saturday 3 mile run
Sunday 3 mile walk or 1 hour gym.

I've started to use frozen peas but do I need to do anything else?
I am around 4 stone overweight which I'm sure doesn't help my knees but I'm desperate to still be able to run in these events.

Any advice welcome. Thanks.

Forgot to say. I have had my running gait analysed and have bought trainers that suit my gait. They are due to get replaced around june/July.

I have clicky knees too. Nothing completely sorts them, but it seems to help a bit if I:

• Warm up and cool down properly. So a good 5 minutes of fast walking, swinging arms etc, before I start to run. And 5 mins of walking or v slow jogging to finish with too.
• Stretch after cool down (not loads of stretches, but just the main leg ones…hamstring, quads, calves, iliotibial band).

Thanks. I don't warm up or cool down properly so ill give that a try. Thank you.