How to fill these gaps window in and out

[Peepeeouch]

My dining room window needs help! It’s over 20 yrs and we’re getting signs of damp at the base of the wall inside. Pictures under the sill inside and then under it outside… same filler or different and is the outside one something to diy?

Get some quotes and see what they say they’ll do.

I was hoping to diy it but there are so many different fillers, caulk and silicones and sealants that I thought someone here might have done similar and could recommend something they used.

Caulk on the inside. On the outside, scrape the existing sealant out and refill with external silicone sealant. They're small jobs and you will get them done in a couple of hours.