Car starts sometimes, wtf gives

[Dee2]

Ok so my car my joy a 2003 x5 4.4 beautiful girl but right now she is bugging and being temperamental. I have a lot going on in my life and cant afford any financial drama. My 37 yr old hubby had 3 strokes and it nearly ruined us financially.

So the car, my key fob has long since died and I do everything manually. Key fob died a few months after I got the car in 2008. As of the early part of this year Id go out to car and occasionally it wouldn't start so Id have it jumped and go on my way. It was a rough winter in NYC for ole girl. Months go by and now I get in the car everything comes on except it wont flip over. I take the key out, get out the car, lock it get back in and then it would start just fine. Thought it was a fluke. Then it happened again some days later I kept trying and then it started. Now its intermittent, sometimes it wont start today but then it will start tomorrow. There was a time when I drove to point a got out came right back it didn't start, I left the key in ignition 2 listened to the radio tried after about 20 mins and it started. Now car wont start for a whole week, had the car jumped several times and nothing. Keep in mind everything else comes on. So at the end of the week the started again just fine for like a week. Then this past Sunday, I got drove about six miles, helped a friend upstairs came back in about 5minutes and the car wont start. I had to leave the car in the Bronx.....

I thought maybe it was the key cause occasionally I would create friction by scrapping it on a zipper and the car would start but now that doesn't even work.

Please help me, I just need for something to go my way. I really dont know what is happening to this car. I have an after market battery Duralast from AutoZone. Could it be the battery or is it the key. $tealer wants 200 for one and this is the only key I have. Its not the kind where I can unscrew and change the battery. I have looked at vids and tried to pry it open to no avail. I dont know what to do and this shit is making me cry daily. I just dont know I really dont know what to do.