bad luck Nicobec. Sounds like you are working with what you have got considering the medication. Reading a race at club level mostly comes down to getting to know those you race with. However, that gets thrown out the window when you race against those you don't know.
Crit's are the only races I stand a chance in so I try to give myself the best chance. Our races all tend to be an hour plus 2 laps, regardless of where I race. These races seem to have a few set patterns to them. When no one gets away for the race they go as follows. Fast pace for the first 20 minutes while everyone is fresh, surges for the next 20 mins while people try to get away, solid yet less frantic for the last 20 minutes as people resign themselves to a sprint finish. The next type is the unsuccessful break. This is the same first 20 mins (or perhaps the break gets away earlier), then the next 20 -30 minutes people either try to bridge or some work together at the front to bring the break back. When the break gets caught people resign themselves to the sprint. The last type of race is the successful break (the least likely in the lower grades I tend to race). Same start as above, then the break goes and usually sticks because either no one want to work to get to them, or they are too strong on the day, and then the last 10 minutes we meander like browns cows hoping for a crash in the break (not really
). Of course that is a broad brush overview but tends to ring true in 90% of my experience.
The "A" graders here will tell a different tale because breaks tend to happen more often than not.
I keep to the front in the first few laps because the real suffering happens at the back. It is a far easier ride at, or near, the front than on the elastic train at the back. At this point though I have to declare I have never been involved in a significant long break in a race with a decent sized field. The longest is two laps. So I tend to either chase the breaks I don't like the look of or hope that others will chase when I don't have the energy mid race. But I tend to know those I race with so that makes it easier. That is the best trick.
Sorry for the ramble (probably nothing in it you haven't already figured out) and good luck mate.
I ride several bicycles, but not at once.