Ex moved without telling me and no contact with child for years now

My ex and I divorced about 7 years ago and there was a child arrangements order, pension sharing and financial order. I live overseas (remarried) but most of my family are in the uk, my ex and child are in the uk. 

My child turns 16 next year. I have not seen her or spoken to her since the divorce. Not from want of trying of course. There is a court order in place to support contact but my ex ignores it. I send cards and gifts and letters. I tried calling every week at the nominated time - never answered (this went on for many years) and then started having issues getting through. I then got a text message to say that I don’t have the right phone number after I sent a “how are you, love dad” text  so turns out the phone has been cut off and reallocated to someone else. When I was back in the uk last year, i tried calling the ex on her landline and her mobile but that number was also cut off. I got in touch with the only 3rd party I know who may be able to get in touch with her and was told that she had moved house 2 years ago and this person had forgotten to send the new details to me. Pretty big thing to forget! Wonder what has happened to the cards and gifts and letters? I now have a new address but no contact numbers. Via this 3rd party I asked to make arrangements to get childs new number but that was ignored. And I asked if a visit could be arranged but told my child didn’t want to.

so I don’t know what to do. 

dragging through court is extremely stressful and expensive for everyone involved which is why I’ve stupidly left it. But my ex is not a reasonable person and even wrote to me once saying I needed to increase the child maintenance or she wouldn’t encourage contact etc. not wanting to be coerced and blackmailed in this way and not knowing quite how to respond without it being used against me somehow, I just ignored it.

I haven’t been in a position to return from overseas until next year but then it’s probably all too little too late. but I will try to establish contact again via this 3rd party unless anyone has other suggestions. I don’t want to just turn up because she will probably call the cops and make some scenario up. 

2nd question is pension sharing order was enacted and she’s had whatever percentage. Can she take any more? my understanding is she cannot. Getting to that age now where I need to be certain on these things. 

3rd question. If my only income is my pension and I am right about the above then can I be expected to pay her maintenance out of this pension if that is my only income? Whilst there is no maintenance order, the judge left it open incase circumstances changed. I would have preferred a clean break. I’m not working at the moment and haven’t been for last 1.5 years but I am still paying the agreed child support in full out of savings. Can I get a variation on the financial order to provide a clean break? I am so scared she is going to come after me for more money and I hate it hanging over my head. It’s really stressful and I kind of bury my head in the sand which isn’t making it better. 

thanks for listening.