Suggest Option For Severe Knee Problems

i have has knee problems for going on 20 years almost all my life with sever pain, ive had physio , tried to build mussel ...everything. but lately its been getting worse, i have 3 small kids and its getting hard to deal with. My doctor told me years ago id need surgery but i never went with it. Just wondering if you think that's a good option now and how long a recovery it might be?