Jimmy, it's not a straightforward game this. I'm not saying you have to keep at it, maybe it's not for you. Maybe you'd be more suited to the bike or weights or whatever. But if you look at most of the fellas who've been at it for years on here - I'm thinking the Terrier, Timeout, Smurf, Elwood, Pounding Rd. (This last named on another comeback if I'm not mistaken) and of course meself!! then you'll see the setbacks have been many and prolonged. All of us have had injuries that kept us out for a year or more. And when you think you're getting back, bang goes something else. It's tough, I'm not gonna lie, but I think we'd all agree that it's worth it in the end. Right now, Carta, who's represented Ireland and has completed some epic races is on the injury list. I believe he's determined to make it back. And remember some of us are well past 50, eh!! Ok, Terrier, Elwood and me. But, if you're willing to persevere, I think you'll make it yet.
One last thing, I believe you might be better off with short to midterm targets. A Half marathon always strikes me as achievable, rather than saying Ok, 4 months to Cork/Dublin/Berlin/Valencia, let the training begin. Pick a 10k, a 10 miler a Half or two and then a couple of years down the line, you'll be well placed to tackle that Full. Good luck with it.
Try myofascia release as well if you can. It's kind of like a massage but more focused on certain areas.
