Any tips & techniques on improving stamina and court footwork?

before i had a good stamina,but after i moved from other country,i stopped playing for maybe 2 months,then when i get back to court i thought i still had the skills, to play same level before, but i was wrong, at first my shots were horrible i guess(for me),but i waited some time and tried to practice on my own again since im new to the place no training partner yet,but then later on i met some player and i started playing with them, i know i had the power and good energy, my strokes were improving again,i feel good again and excited when playing, but lately i�ve noticed that sometimes in middle of the game or rallies i kinda loose my stamina, i felt like im runnig out of air then and then sometimes i got off with my footwork,and aslo i tend to stretch my self a bit lately as well since my footwork off im making short work by stretching sometimes too much,which i know is wrong. im working on those things again,so i hope anyone out there could suggest, i need your help.�thanks a lot��