Financial worries on top of the pain!

I have had a couple of discussions on here before very helpful. I am just feeling really down today and this seemed the best place to air my worries I hope that's ok. Yesterday afternoon I had 3 hours in a Primary school (I'm a teaching assistant) very close to me a 5 minute walk in fact. I work for an Agency who I've told that I can't do Special Needs or children with behaviour issues or runners (they are children who try and escape from you and usually move much quicker than you!!) anymore. I try and be honest about my limitations and positive about what I can still do. Yesterday's role was a 1-1 with a lovely little boy in Reception with suspected autism, went well I felt confident that I could build up a good relationship with him. Unfortunately I've had to say no to the role because it also involved another child for half an hour a day and this boy does do runners, I saw him do it four times! I've gone from being open minded to feeling totally useless, I can accept that at 61 I am not going to be as quick as I was 20 years ago, but I feel as if Osteoarthritis of the hips is preventing me from even surviving. Because at the end of the day, I am on my own, Universal Credit isn't enough to live on (monthly bills are still having to be paid) I can't retire (not got enough in my pension pot to live on till 66) I've been told (by a council so called welfare expert) that I have no chance with PIP so what choice do I have but to keep putting myself through situations like the above? I do have a Fitnote but that doesn't help financially just that UC aren't down on me like a ton of bricks for not 'actively looking for work' as they put it. I told the Agency that I am looking for part time work now, trouble is the pay isn't very much and UC take 63p off your benefit for every pound you earn.

By the way I do exercise every day as someone else mentioned the Exercise with Leon thing on here is good, I also have exercises in the Osteoarthritis handbook from Versus Arthritis. I have friends who are probably fed up of me, it's hard for someone who doesn't suffer from arthritis to understand. Being type 2 diabetic narrows my options as far as painkillers are concerned so I try to keep them to a minimum. It is so very hard to be positive though I think a lot of you on here are, so put me to shame. Thanks for reading this,

Robin59 xx