How do I know if I'm fixed? Calling all runners!

[Vsaway]

Hi, I'm a 59 year old male who's been running (Half and full Marathon) for about 12 years (previously a regular swimmer and cyclist). I've always been fit and lived what I thought was a healthy lifestyle, never smoked, little alcohol, avoided fast foods, minimal red meat, mostly chicken and fish. I did however eat a lot of carbs before and after runs - carb loading, and had regular biscuits and cakes with afternoon tea!

Training for a half this year I started to have issues, palpitations after runs, excessive recovery times , Then I had a couple of serious chest pain sessions that I put down to post covid symptoms and ignored, but finally resulting in a third when my wife took me to A&E. The outcome was diffuse Atherosclerosis and a double heart bypass on 07/07/23. Recovery wasn't straightforward, infections, effusion in the chest and pericardium, but that all got sorted within about 8 weeks.

I want (need) to get fit again. I was offered the rehab course but then not permitted to attend as I still experienced chest pain when I exerted myself - this was at week 10. I've tried seeking further medical advice but it's difficult as the services are so stretched and I feel all they want to say is don't exert yourself. For someone who has been as fit as I have that's like saying live life in black and white when you've known colour. I'm not ready for black and white.

Anyway I've started going to the gym, walking on a treadmill (built up to 2 miles - slight incline - 3mph). I've tried to jog as well, 200m then slowly further to 500m. Walking is fine, jogging less so. It just feels wrong in my chest. The minor surgical point pains I can ignore, but the tightness inside my chest behind my sternum is very off putting. I can push through it and I haven't died yet

The issue is I have no idea what to expect at this stage (16 weeks), Is this normal? Should I keep pressing on? Is there another fit person out there who knows exactly what I mean who can say I had the same and it went away as the months rolled by? I realise I'm out of shape but it doesn't feel like being out of puff, it feels more fundamental, like the pump isn't up to it. Should I just run out of puff? Did this deeper feeling hold you back at the start, but go away - or did you never have it?

I'd just like to talk to another fit person who came back from where I am today.

Thanks for taking the time to read this. Please help - I feel totally on my own in this.