Recently, since about 5 months ago, Minecraft's Survival Multiplayer feature has not worked properly. Some Symptoms:

• Upon connecting, I find myself falling for a good 3 minutes
• Chunk downloading takes ages
• I see messages minutes after they are sent
• Blocks I break come back, on servers that I'm whitelisted
• Mobs are fucked up

This has been happening on every server I've been to.

I've been given the opportunity to be a part of a smp lp with my family, but I can't now, and I really would like to. Please help me fix this.