It's tough to examine based on the pics, but I suspect that you may need to buy a new roll of 60/40 rosin core. What you have isn't working well, many of your problems stem from that, not lack of talent.
You may find it easier to use the molten solder to transfer the heat to the work, rather than heating the work first. That way, you are less inclined to overheat the work.
Your initial picture shows very badly tarnished leads. Never solder with parts that look that bad, as the flux is not designed to cut through that stuff very quickly. Somebody said scotchbrite or abrasive pad, excellent suggestions. The leads must be shiny before soldering, none of that black or dull grey stuff. If you clean the leads, try to tin one or two with the solder first, just to make sure the leads will solder before stuffing them into the holes.
From the pic, it looks like you still have open holes. The solder fillets should completely surround the leads, and form a nice "hershey kiss" type of solder mound at the lead, but have a simple slope to plane at the bottom, don't overfill with solder.
Keep up the good work.
jn